Although I did not have the issue in the last few days, I can confirm there’s been an issue for some time.
I think I also had it with the owner profile, but it’s mostly with a secondary profile that I had this issue.
When it happens, the unlock screen will also shut down in 10 seconds, since I have a long password, and typing nowhere is seemingly not taken as a user action, even though I think it even happens when characters are added in the password field. This mostly happens when I tap the lock icon; swiping up to uncover the unlock screen will usually put the focus on the password field.
I also have a high failure rate when entering this secondary profile password; in contrast, I often successfully enter my owner profile on the first try. Of course, it is perhaps unrelated, but still is quite surprising sometimes.
This is happening with a Pixel 8, the secondary profile in question has English (UK) as the main and only language, the keyboard is the AOSP one set in another language, and I also have the Magikeyboard (KeePassDX).