weston-8.0.0: eventX input devices are ignored after updating systemd from 244 to 245

I start weston from a systemd service as described in #7 which works until I update from systemd-244 to systemd-245 (no other changes and I can reproduce this by switching systemd versions back and forward.)

With systemd-244:

weston[390]: [09:57:30.470] event8  - Power Button: is tagged by udev as: Keyboard
weston[390]: [09:57:30.470] event8  - Power Button: device is a keyboard
weston[390]: [09:57:30.488] event9  - Video Bus: is tagged by udev as: Keyboard
weston[390]: [09:57:30.488] event9  - Video Bus: device is a keyboard
weston[390]: [09:57:30.492] event7  - Power Button: is tagged by udev as: Keyboard
weston[390]: [09:57:30.492] event7  - Power Button: device is a keyboard
weston[390]: [09:57:30.497] event0  - Rx504B  Ver:3.03: is tagged by udev as: Keyboard
weston[390]: [09:57:30.498] event0  - Rx504B  Ver:3.03: device is a keyboard
weston[390]: [09:57:30.503] event1  - Rx504B  Ver:3.03: is tagged by udev as: Mouse
weston[390]: [09:57:30.503] event1  - Rx504B  Ver:3.03: device is a pointer
weston[390]: [09:57:30.526] event2  - Rx504B  Ver:3.03 Consumer Control: is tagged by udev as: Keyboard
weston[390]: [09:57:30.531] event2  - Rx504B  Ver:3.03 Consumer Control: device is a keyboard
weston[390]: [09:57:30.545] event3  - Rx504B  Ver:3.03 System Control: is tagged by udev as: Keyboard
weston[390]: [09:57:30.545] event3  - Rx504B  Ver:3.03 System Control: device is a keyboard
weston[390]: [09:57:30.554] event4  - Rx504B  Ver:3.03: not tagged as supported input device
weston[390]: [09:57:30.557] event4  - not using input device '/dev/input/event4'
weston[390]: [09:57:30.623] event5  - ILITEK ILITEK-TP: is tagged by udev as: Touchscreen
weston[390]: [09:57:30.623] event5  - ILITEK ILITEK-TP: device is a touch device
weston[390]: [09:57:30.686] event6  - ILITEK ILITEK-TP Mouse: is tagged by udev as: Mouse
weston[390]: [09:57:30.687] event6  - ILITEK ILITEK-TP Mouse: device is a pointer
weston[390]: [09:57:30.745] libinput: configuring device "Power Button".
weston[390]: [09:57:30.745] libinput: configuring device "Video Bus".
weston[390]: [09:57:30.745] libinput: configuring device "Power Button".
weston[390]: [09:57:30.745] libinput: configuring device "Rx504B  Ver:3.03".
weston[390]: [09:57:30.745] libinput: configuring device "Rx504B  Ver:3.03".
weston[390]: [09:57:30.745] libinput: configuring device "Rx504B  Ver:3.03 Consumer Control".
weston[390]: [09:57:30.745] libinput: configuring device "Rx504B  Ver:3.03 System Control".
weston[390]: [09:57:30.746] Touchscreen - ILITEK ILITEK-TP - /sys/devices/pci0000:00/0000:00:15.0/usb1/1-4/1-4:1.0/0003:222A:0001.0004/input/input6/event5
weston[390]: [09:57:30.746] libinput: configuring device "ILITEK ILITEK-TP".
weston[390]: [09:57:30.746] input device event5 has no enabled output associated (none named), skipping calibration for now.
weston[390]: [09:57:30.746] libinput: configuring device "ILITEK ILITEK-TP Mouse".
weston[390]: [09:57:30.746] input device event6 has no enabled output associated (none named), skipping calibration for now.
weston[390]: [09:57:30.746] DRM: head 'DP-1' found, connector 143 is disconnected.
weston[390]: [09:57:30.753] DRM: head 'HDMI-A-1' found, connector 152 is disconnected.
weston[390]: [09:57:30.781] DRM: head 'HDMI-A-2' found, connector 158 is connected, EDID make 'ADA', model 'unknown', serial '1'
weston[390]: [09:57:30.783] Registered plugin API 'weston_drm_output_api_v1' of size 24
weston[390]: [09:57:30.784] Chosen EGL config details: id:   6 rgba: 8 8 8 0 buf: 24 dep:  0 stcl: 0 int: 1-1 type: win vis_id: XRGB8888 (0x34325258)
weston[390]: [09:57:30.784] Output HDMI-A-2 (crtc 67) video modes:
weston[390]:                800x480@65.7, preferred, current, 32.0 MHz
weston[390]: [09:57:30.784] associating input device event8 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event9 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event7 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event0 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event1 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event2 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event3 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event5 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.784] associating input device event6 with output HDMI-A-2 (none by udev)
weston[390]: [09:57:30.785] Output 'HDMI-A-2' enabled with head(s) HDMI-A-2

With systemd-245:

weston[393]: [09:49:29.067] event8  - failed to create input device '/dev/input/event8'
weston[393]: [09:49:29.105] event9  - failed to create input device '/dev/input/event9'
weston[393]: [09:49:29.149] event7  - failed to create input device '/dev/input/event7'
weston[393]: [09:49:29.169] event0  - failed to create input device '/dev/input/event0'
weston[393]: [09:49:29.202] event1  - failed to create input device '/dev/input/event1'
weston[393]: [09:49:29.207] event2  - failed to create input device '/dev/input/event2'
weston[393]: [09:49:29.211] event3  - failed to create input device '/dev/input/event3'
weston[393]: [09:49:29.213] event4  - failed to create input device '/dev/input/event4'
weston[393]: [09:49:29.276] event5  - failed to create input device '/dev/input/event5'
weston[393]: [09:49:29.336] event6  - failed to create input device '/dev/input/event6'
weston[393]: [09:49:29.336] warning: no input devices on entering Weston. Possible causes:
weston[393]:         - no permissions to read /dev/input/event*
weston[393]:         - seats misconfigured (Weston backend option 'seat', udev device property ID_SEAT)
weston[393]: [09:49:29.336] failed to create input devices
smartd[532]: Device: /dev/sdb [SAT], SAMSUNG HD103SI, S/N:S1VSJ9BZ617158, WWN:5-0024e9-202ae6bc2, FW:1AG01118, 1.00 TB
smartd[532]: Device: /dev/sdb [SAT], found in smartd database: SAMSUNG SpinPoint F2 EG
kernel: weston[393]: segfault at 10 ip 00007f959438970c sp 00007fff24adb858 error 6 in libc-2.31.so[7f9594276000+146000]
kernel: Code: 0c 08 00 4c 8d 1d 24 59 05 00 4f 63 0c 8b 4f 8d 0c 0b 41 ff e1 0f 0b 0f 1f 80 00 00 00 00 48 83 ea 10 66 0f 6f 0e 48 83 c6 10 <66> 0f 7f 0f 48 83 c7 10 48 81 fa 80 00 00 00 f3 41 0f 7f 00 77 4e

The segfault is not the target of this issue. libinput list-devices shows the exact same output on both versions of systemd:

Device:           Power Button
Kernel:           /dev/input/event8
Group:            1
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Video Bus
Kernel:           /dev/input/event9
Group:            2
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Power Button
Kernel:           /dev/input/event7
Group:            3
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Rx504B  Ver:3.03
Kernel:           /dev/input/event0
Group:            4
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Rx504B  Ver:3.03
Kernel:           /dev/input/event1
Group:            4
Seat:             seat0, default
Capabilities:     pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      n/a
Scroll methods:   button
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   flat *adaptive
Rotation:         n/a

Device:           Rx504B  Ver:3.03 Consumer Control
Kernel:           /dev/input/event2
Group:            4
Seat:             seat0, default
Capabilities:     keyboard pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    disabled
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           Rx504B  Ver:3.03 System Control
Kernel:           /dev/input/event3
Group:            4
Seat:             seat0, default
Capabilities:     keyboard 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           ILITEK ILITEK-TP
Kernel:           /dev/input/event5
Group:            5
Seat:             seat0, default
Size:             482x267mm
Capabilities:     touch 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      identity matrix
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Device:           ILITEK ILITEK-TP Mouse
Kernel:           /dev/input/event6
Group:            5
Seat:             seat0, default
Size:             482x267mm
Capabilities:     pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      identity matrix
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

weston.ini:

[output]
name=HDMI-A-2
transform=270

[core]
idle-time=0

[input-method]
path=/usr/libexec/weston-keyboard

[keyboard]
keymap_layout=gb

Distribution: Gentoo amd64 stable

Kernel: Linux localhost.localdomain 5.8.3-gentoo #1 SMP Sat Aug 22 18:17:27 BST 2020 x86_64 Intel(R) Celeron(R) J4105 CPU @ 1.50GHz GenuineIntel GNU/Linux