This seems to be an issue with Windows 10 and Fences 3.08 and has stemmed back several years ever since Windows 10 was available according to other forums.
No, not the issue you are presenting. The only time I have ever seen UAC prompt, for when Fences is of a concern, is if Fences is being run as Admin.
If it helps with any other apps you are running (perhaps a Windows Explorer replacement), Fence runs in the Windows Explorer process.
The only next recommendation I would be able to offer, and it's just a test, would be to try a clean boot:
This will help eliminate any other app or service from being a contributor.