Ok, this sounds like normal behavior (if I recall my OSX and Windows Lync clients do this) this is because the network connection is severed when it goes into hibernation. It should sign straight back in though once network connectivity is restored.
Lync won't stay signed in when the machine is hibernated.
Hi,
Did you meet the issue that when Mac come back from sleeping, Lync client need to login manually?
It seems to be a known issue for previous Mac Lync version. If you also meet the issue, please try to install the latest version of Lync for Mac and test again.
Best Regards,
Eason Huang
The issue was resolved. Unfortunately, I was using a Windows keyboard on a MAC machine.