Two different issues in the attached file. 4.2.1 has some sync issues that moving back to 4.1.33 resolves.
[Note: I never loaded 4.2.0 ]
In four(4) cases across two different days a 30 min repeating appt time adds hours to 0600 from different start times and will not sync saying both Outlook and Google have changed - however deleting from both Outlook 2021 and Google - it comes back. I tried reset matches - no help.
The other issue doesn't report to the sync details & log window, but has several notes and is included at the bottom of the attached file as it may have some useful debug info.
I should add that after going back to 4.1.33 and it working without the issue, then installing 4.2.1 again, same issues. Going back to 4.1.33 good again...
I then loaded 4.2.0 and the issues happens there too... Back to 4.1.33 all good again.
In both 4.2.0 & 4.2.1 the sync would start with every appt showing as Outlook updated Google
UPDATE - While I still do not understand the issues shown in the log file, I do have more information. I noticed that I have set the SYNC WINDOW for months PAST to 1 month. If I change that to 4 months so that the 1/2/25 and 1/15/25 are covered, then I get the same issues for those 4 appointments that I get with 4.2.0 & 4.2.1.
So it looks like the Months PAST setting with 4.2.0 and 4.2.1 are going back beyond the one month set for some reason. In all 4 cases these are recurring appointments where one occurrence was changed. And maybe this is why they come back after been deleted from Outlook and Google and why the check is going back more than a month... the later versions follow the entire recurring event time window.
Sounds like the same or similar issue mentioned here:
https://sourceforge.net/p/googlesyncmod/bugs/1408/
And earlier in the Support subforum:
https://sourceforge.net/p/googlesyncmod/support-requests/1026/