P: Edit/Sync Photo changes the Capture Time.

It did take a couple tries for it to fully revert the dates, but it got there.  I selected all 69 photos affected in my library, hit the Revert Capture Time menu item, and saw the Sync Activity box fill up with items.  But then I selected all those photos again when it was done, and "Revert Capture Time to Original" was still available to be clicked.  Had they all been fully reverted, it would be greyed out.  That told me it somehow missed some, or some artifact sync'd back from the cloud and re-broke some of them.  In the end, I moused through all the images and found just two where the menu option was available.  Even then, reverting them didn't really change the time visibly from the time displayed in the Metadata pane.  Like it must have reverted them by fractions of a second.  A rounding error.  Nothing like the 7 to 9 hour jumps it was making before.  So it seems to holding.  Nothing has jumped around in the hour or so I've been watching it.

My bad. It seems my preferences were indeed all reset when I updated to v14.1.1 but the font size issue was corrected by changing to the "Larger" size (due to Automatic defaulting to "Largest" for some reason).

Appreciate the quick update to fix what was looking like a major bug. I haven't noticed any sync/date issues since updating to v14.1.1 -- fingers crossed they don't reappear -- but I did see major instability issues after installing the update. Multiple blue screens of death and forced restarts were required before I could even open LR without crashes. Plus all of my LR preferences were wiped and the menu text is all big and ugly. Can't seem to fix the text issue. The "Automatic (default)" font size is still big and ugly and the "Medium" font is too small to read. I don't remember having this issue before.

I was having this issue and it was driving me batty.  14.1.1 seems to have fixed it, but I did have to do the "Revert Capture Time" trick to fully fix it.  Thanks Adobe for correcting it quickly.

Try this:  In the Librart Grid view, select a couple of the incorrectly time-stamped images. Go to the Metadata menu and choose Revert to Original Time. If that works, you should be able to do that the the remaining photos all in one swoop. 

@mitchell30927698  
The team advises: Use Metadata > Revert Capture Time to Original option for these files. 

I recommend testing a single file first...

I installed the update and no new images are impacted. The ones that have been impacted, remain in their faulty locations in my timeline though. Any pointers on how to solve this? I'm matching GPS data with my images and for that to work I need the capture time to be exactly right.

If you still see the problem after the update to Lightroom Classic 14.1.1, then pausing sync in Lightroom Classic is enough.

Is disabling syncing on LrC enough, or do you need to disable it on the mobile app as well?

@Rikk Flohr: Photography I may have spoken too soon. I'm still seeing occasional photos jumping around. It's far less frequent than before the update, but not entirely resolved. I'm not sure if I can provide any additional helpful details.