I'm on Catalina 10.15.7 (19H1419), not even sure if that's relevant.
I've seen the "loginwindow seems to be preventing text expansion" a LOT more often recently, at least once a day.
Also, the previously 100% reliable "lock then unlock" process often no longer works.
The "solution" documented here: This can be resolved by restarting your Mac, or logging out fully and logging back in.
is not practical for anyone doing non-trivial work, where a reboot, or even a complete logout, is a serious disruption. The amount of context lost with multiple shells, tmux/screen sessions, many trees of browser tabs, multiple editors, and many other apps is a serious issue. It's not viable to say "just reboot". It's a good 15 min of time to restore context and some can't be easily restored.
IMO, letting that solution stand is a lack of respect for the user's time.
Either this needs to be fixed (ie: stops happening), or we need a command that can be run to address the "loginwindow seems to be preventing ... " state.