one problem could be: the user on Windows does not have the TheocBase permissions. This is not the case here (since you see the changes on the iOS).
In your case: go to the device that does not sync. In TB, hover over the cloud symbol where you normally synchronise, and click the exit icon next to the word 'Dropbox'. Close TB and give it some time. Launch TB and reconnect to DB.
If it still doesn't work:
Disconnect TB from Dropbox again.
Go to the Windows computer. Make a copy of the theocbase.sqlite file somewhere safe. (Find the file in TB Settings | Open Database location).
In TB hover over the cloud symbol (do not click it) and move down to 'Delete cloud Data' in the bottom, and click the cloud symbol with the recyle bin icon. Confirm. Within one or 2 seconds, it will ask you: Do you want to synchronise? Click Yes (!). Your data will not now be uploaded into a new cloud file.
Reconnect the other device's TB to DB. Devices may warn you that the cloud data were deleted, but you know there are new cloud data now. So proceed to synchronise.
Hope that works.