Sorry to hear about the trouble. As mentioned that Export PDF feature is causing the error "Not connected to internet", so is that conversion was tried through the web browser Adobe Document Cloud or through Adobe Reader desktop application?
You may check the following steps-
If nothing works, then follow the instructions given in the similar discussion here: Adobe Export pdf says no internet connection and find the list of Adobe ports and URLs with you via the private message which you need to whitelist on the network and firewall, share it with your IT team.
Let us know if the solution provided above doesn't help!