Updated LR CC not able to connect to server

[Asi9999]

Hi

I'm on iMac, fully updated (Catalina 10.15.7) using updated Lightroom CC (ver 3.4). 

Everything has worked for years, but not suddenly "Unable to connect to server" ie I cant upload, sync etc.  No changes to wifi, firewalls etc. 

I can access via mobile app on iPhone and Ipad (on same wifi network) and via browser on same computer/network.

I have tried to restart etc but still continues. Sometimes it has connection for a short time, like 2-3 min, then again "Unable to connect to server". 

What to do ??  Its super frustrating...

Appreciate any help and advise.