If you use a german - or other than english - keyboard you must reconfigure your session.
wayfire: wayfire.ini
[input]
…
xkb_layout = de,us
xkb_model = “1003:8258:MNT_Reform_Keyboard”
cage/Xwayland: startup script like reform-wmaker before the cage command:
…
export XKB_DEFAULT_MODEL=“1003:8258:MNT_Reform_Keyboard”
export XKB_DEFAULT_LAYOUT=“de”
cage…