So this is a weird problem. If I use control \ on the dropbox sign in page, dropbox won't authenticate me and says bad password. I just have ONE dropbox login entry in 1PW. However, if I do a copy paste from 1PW into the password field, then I am logged in. 100% reproducible. I do notice the number of 'dots' that get pasted in with control \ is shorter than when I manually paste from 1PW.
1Password Version: 7.0.508
Extension Version: Not Provided
OS Version: Not Provided
Sync Type: Not Provided