Windows 11 File History recopies unchanged files whenever its Control Panel page is opened

Thank you very much for taking the time to provide these detailed and practical suggestions.

Your point about distinguishing a fully completed additional backup from repeated attempts to finish an incomplete cycle is helpful. The initial backup of approximately 38 GB definitely completed. After I reopened the File History page, another run started and consumed approximately another 38 GB. However, I did not separately record its final completion time before conducting the later tests, so I agree that this detail should be verified more carefully.

If I can safely repeat the test with sufficient free space, I will allow one additional run to finish completely, record its completion time and then reopen the File History page. I will also compare the SHA-256 hashes and modification times of an unchanged source file and its different backup versions.

I previously tried checking the FileHistory-Engine Operational log through PowerShell, but Windows reported that no matching event log existed on the computer. I will include that result, together with my Windows 11 build 26200.9550, in the Feedback Hub report.

For now, I have turned off File History to prevent the backup drive from filling again, and I am maintaining a separate backup. Thank you again for your guidance.