After this update, I cannot switch the keyboard layout in Xfce

[cscs]

Are we to understand the fcitx5 package was added?

If you werent using fcitx5 before and its not a dependency of any other package then you can (should?) remove it.

Possibly related thread?

Input method - current user's input method forced to change?

Well, its not definitive but so far I am tending towards When considered alongside the use of pamac this seems the most likely candidate for me - whether it occurred previously and established the AUR package or was created by some confusion during this single transaction. Something with sdl2 being in the AUR and have the fcitx5 build depend and the use of pamac (repo+aur). Nope. Neither sdl2-compat nor sdl3 require fcitx5. Even if you reverted to sdl2 from the AUR fcitx5 would still no…