Solved Losing time - Clock sometimes out of sync on startup since installing Windows 11 24H2

Hi all,

Since installing Windows 11 24H2, the time in Windows is sometimes out of sync, losing a about 0.1-0.2 seconds per minute, which adds up over the course of a day (and is super frustrating when working).

The CMOS battery has been changed to a new one (the old battery proved to still be holding charge, though).

This issue does not occur on Windows 11 23H2.

Motherboard, CPU and RAM all about 2 months old: X670E Gigabyte Aorus Master (Bios v. F33d), Ryzen 7 7800X3D, G.Skill Trident Z 6000 CL30.

I haven't been able to work out the exact conditions for when this occurs.

I have flashed older bios versions (F21, F22, F33c) and cleared CMOS, etc. in addition to changing the battery.

I have recorded the time on the motherboard BIOS ticking over, and it does not lose time when I have observed it.

If I reboot to BIOS and set the time manually after I notice the issue, the next boot of Windows keeps the time. Sometimes, though, Windows doesn't sync the slipping time to BIOS - so sometimes the BIOS time is still correct even if it is a few to many seconds out in Windows.

When the symptom does occur, I notice that the time can start falling behind even if just at the Windows login/lock screen (I always sign out before shutting down due to having two Windows accounts - both local, one at administrator level).

It's a strange and also infuriating issue.

Has anyone else experienced this or spotted whether this is a known issue with Windows 11 24H2?

Regards,