All three of my devices are running the latest OSes.
I don’t use Hide My Email; I do use iCloud Keychain.
The link you provided to “How to find saved…” told me to do what I had already done. That’s how I got the screen grab above. That’s what my passwords list looks like, and if I click any password like that to get info, the username and passwords fields continue to look like that — gibberish.
Some of my passwords look fine and auto filling usernames and passwords for those ones works as expected, but trying to auto fill a sign in screen for one of the gibberish ones fails, of course. Possible meaningful tidbit: the ones that work are regularly used; the ones that are gibberish are quite old and may not have been used in months.
Thanks for your help so far.