Not sure why my 1st reply never posted. I'm not one of the people have the problem, so I have wait for a cooperative person to perform your tip #2. Answer to your #1: no Windows users are having this problem.
I'm hoping to do some lower level troubleshooting in order to see what is actually causing the problem. #4: no, there are no service upgrades happening to our account right now.
Hope to have someone reinstall Lync and see if that resolves the issue this week.
Regards
Doug