Why is Safari no longer auto-filling in passwords?

Up until this morning, Safari and Keychain were working and would auto-fill in passwords to various websites. I changed no preferences, deleted no keychain items, nor made any changes to the security settings, but now Safari refuses to fill in passwords. I also can't find these passwords in the Keychain Access; if I *change* the password, Safari asks if I would like to change the stored password. If I say 'yes', there is still no password recorded in the Keychain. If I try to make a new account on a website with a new password, Safari pops up with its usual suggested password; if I select it and move forward, I can not find this stored password anywhere (either Keychain or Safari). ***? I should just use 1Pass and Chrome.

The only weird thing that happened was I was trying to select between two different accounts/passwords on a website; it gave the usual beige/yellow selection box for selecting which stored password/acct to use, then it just went away before I could select something. After that, the above behavior started.