Hi Gasser76,
For Typekit font sync to work, the following domain names need to be whitelisted:
(Ports 443 & 80 also need to be open.)
There is more information on other CC services in the "Adobe Creative Cloud Network Endpoints" document:
And as kglad said, Adobe Support would be the next step if you still can't get the Creative Cloud application network connection working.
https://helpx.adobe.com/contact.html
I hope that this helps; let me know if you have any other questions! Best,
-- liz