I am experiencing the exact same thing in this article on my iPhone X and iPad Air 2. My 2 windows 10 pro systems are working just fine.
1Password Version: 126.96.36.1996
Extension Version: 188.8.131.52
OS Version: Windows 10 Pro
Sync Type: Dropbox
Referrer: forum-search:iphone x and ipad air 2 stuck in a constant sync