First make sure that all of your devices are on the same version. There was an update a version or two ago that broke backwards compatibility with iCloud. This may have started the problem. Of course with trakt down that doesn’t help. I would pick one device as your master and then delete and reinstall the others so they get a fresh copy from iCloud. Perhaps disable and reenable iCloud for infuse before reinstalling. maybe keep the desktop version since you have to delete the extra system files that aren’t fully self contained in the app like on iOS.
Thanks for your help! It looks to be working partially. Progress!
Desktop seems to push sync data out okay, but not pulling to match other devices.
I had signed out of all my iCloud devices and signed back in. Deleted and reinstalled everything but the Apple TV version. I waited an hour and it looks like the desktop version made an effort to sync. There is an episode off by one being displayed on Desktop (episode 11 on other devices and episode 10 on desktop). I have marked them as watched manually and Apple TV and iOS sync quickly. Desktop still seems to be the remaining issue.
Are you seeing any errors in the Settings > Library menu for the iCloud Sync item?
Does triggering an iCloud Sync there help?
Are you logged into Trakt on any devices? Trakt has been down for the last week or so, so if one device happened to get sync data before they went down and others didn’t, then that could also lead to some weirdness.
You may also check to ensure Infuse is enabled for syncing with iCloud Drive in System Settings > iCloud.