MAC Teamviewer 12 - Not ready. Please Check your connection

Hello,

for about 1 week I have a problem. We have bought licence for our company and using Teamviewer 12 (on WIN and MAC computers).

I have a problem with "Not ready. Please check your connection" in Windows and MAC too.
I already tried to disable ESET Cyber Security in MAC and ESET Internet Security in WIN, no result. Tried to reinstall both computers, no result.

Just tried to change DNS in my network adapter to 8.8.8.8 and seems it works fine now.
But I don't want to use Google DNS. Any solution please?

Have Telekom Slovakia.