I have waited to report this - but it has been a problem for a long while. When on my Mac with 1Password, if I edit any login and click into any field, the field appears to go blank - it isn't, the text is merely white for the majority of fields, however, the password field is different (I'm guessing you used a secure password field so it is responding differently, but still a mess and unusable).
Happy to provide a short video or image.
1Password Version: 3.8.22
Extension Version: Not Provided
OS Version: 10.11
Sync Type: Dropbox
Referrer: forum-search:visual problem during edit