Since updating to 4.2.1, all contacts and all appointments update on every sync though nothing has changed on either Outlook or Google sides. Takes 11 minutes. Win 11 Pro. Will revert to previous 4.1.x version but some users report that after the first sync the problem remains.
Probably the same or similar issue as reported here:
https://sourceforge.net/p/googlesyncmod/bugs/1410/
https://sourceforge.net/p/googlesyncmod/bugs/1408/
I can confirm that this is happening on my wife's computer with 4.2.1 but not on mine with 4.1.33. I'm going to try to downgrade hers to 4.1.33 to see what happens.