Funny saved password behavior in Safari
MacMini (2012) running High Sierra. This has an admin account with a longish password, and my wife and I each have user accounts with no passwords - I did this so we can fast user switch without entering PWs all day long.
Anyway, on her account (but not mine) the option to use a saved user name/password in Safari (for web sites, etc) pop up normally but only for an instant, and then disappear (after maybe half a second). If you click on the icon that appears on the right in the user name or password fields, it does the same - flashes briefly, then disappears. It's long enough to see the user name, but not long enough to click on fill-in-password-for-this-site.
All these things work fine on my account.
Any ideas?
Mac mini, macOS 10.13