That’s showing an iCloud sync location is active. However, as mentioned in the forums more than once, it is quite possible iCloud has stalled - a condition over which we have no control, nor can we even detect it. We can’t reproduce this issue, and some have said it “just started working!”
Here are a few things people have said “worked” , though we obviously can’t test it since we can’t reproduce it. I would try them individually, starting with the simplest…
Reboot the problematic device(s).
In DEVONthink’s Preferences > Sync , disable the iCloud location and quit the application. Relaunch DEVONthink and re-enable the sync location again.
In iOS’ Settings > your Apple ID > iCloud, try disabling and re-enabling iCloud Drive and DEVONthink.
In iOS’ Settings > your Apple ID, sign out of iCloud and sign back in.
In macOS’ System Preferences > Apple ID > Overview, sign out and back in.