Screen blanking with "idle-time" does not work with "kiosk"-shell

I tested "idle-time" screen blanking with following simple config with X11 and drm backends. Screen blanking worked fine with desktop shell but not with kiosk shell. Both started weston-terminal and worked otherwise fine. Tested Weston versions were the latest from gitlab (June 22th) and 13.0.0 release.

[core]
idle-time=2
#shell=desktop                                                                                                             
shell=kiosk
[shell]
locking=false
[autolaunch]
path=/usr/bin/weston-terminal
watch=true