The issue should be fixed with https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1365 which is pushed to gnome-3-36 branch as well as master.
- Bug#964738: gnome-shell-extensions : On screen keyboard has... Emre Uyguroglu
- Bug#964738: Turns out this was an upstream bug Emre Uyguroglu
- Bug#964738: gnome-shell-extensions : On screen keyboar... smcv