So, as of the newest iOS beta, it seems that Apple has changed a LOT of things inside of Safari. (I wouldn't know, they never allow public beta testers access to the change logs...) Like, the popup for entering a username and password for simplified access control in NGINX... The box is completely different.
But, that plus no-password filling? Weird...
The username/email drops in just fine, but I am not able to have the password auto-fill in any page. (Side note, appleid.apple.com on my iPhone wont fill either field)
1Password Version: 6.5.2 (652001)
Extension Version: Not Provided
OS Version: iOS 10.3 (14E5230e)
Sync Type: DropBox