Thanks for the quick response kglad. I went through all of those steps and they all check out fine. I found that page earlier but did not go through it since it seemed to apply to issues with activation.
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.
I hope that this helps; let me know if you have any other questions! Best,