Comment 3 for bug 2003581

This comment is a guess, and I may be completely wrong, but I wonder if this happens in Ubuntu on Xorg only. If so, it may be related to the fact that ibus wasn't always automatically enabled at the start of the session.

That issue was fixed in 22.04 via bug #2007379. So, @nix, it would be interesting to know if the issue is still present after you have upgraded the im-config package to version 0.50-2ubuntu22.04.1.