This isn't "new," but it's definitely ongoing and extremely frustrating.
I have some sites (two in particular, Amazon AWS and Volgistics) which require more than just Username and Password for login. They also require an Account ID or something else to that effect. That account ID is stored in the Web Form Details section.
For some accounts this is easy for me to key in by hand (it's my company name or something else to that effect) while in others it's a 10+ digit numeric ID which there's no way I'm going to remember with infrequent use, meaning I have to dig deeply into the entry and expand the form details, copy them, then paste them into the form before I can log in. This is especially frustrating when auto-login is enabled in 1P and the form gets submitted missing information and you end up getting thrown back to an error page.
1Password Version: 7.1-BETA3
Extension Version: 188.8.131.52
OS Version: OS X 10.14
Sync Type: 1Password