FiiO UTWS3: no audio in HSP/HFP profile: mSBC buffer overrun, dropping data

• PipeWire version (pipewire --version): 0.3.42
• Distribution and distribution version (PRETTY_NAME from /etc/os-release): Gentoo Linux
• Desktop Environment: Sway
• Kernel version (uname -r): 5.15.2-gentoo-hardened1
• BlueZ version (bluetoothctl --version): 5.62
• lsusb:

Bus 003 Device 003: ID 8087:0029 Intel Corp. AX200 Bluetooth

• Bluetooth devices:

Device 40:ED:98:1A:75:9F FiiO UTWS3 L

Description of Problem:

I have a set of FiiO UTWS3s that do not have any audio input or output in HSP/HFP profile mode. They will pair and work perfectly in A2DP mode, but as soon as I switch the profile to HSP/HFP, all audio stops. I can reproduce this with both of the FiiO UTWS3 units (left and right).

How Reproducible:

Pair and connect FiiO UTWS3 with pipewire and wireplumber running. Switch the profile to HSP/HFP mSBC in pavucontrol. Try playing or recording audio and observe there is no audio.

Steps to Reproduce:

1. Ensure pipewire and wireplumber are running.
2. Pair and connect FiiO UTWS3s.
3. Switch the audio profile to HSP/HFP mSBC in pavucontrol.
4. Try playing or recording audio.

Actual Results:

No audio output or input from the FiiO UTWS3s.

Expected Results:

Audio output and input works.

Additional Info (as attachments):

pw-dump.log pipewire-bluez.log