Make sure that WowVoiceProxy.exe is allowed through the firewall. That’s the number one reason why it would have issues connecting and cause the load screens to wait for the connection to timeout. It’s located in World of Warcraft\retail\Utils\
You can check and add rules by pressing start+r to open a run prompt and then type wf.msc
Check to list on both the inbound and outbound tabs to make sure there isn’t already a rule for it, if there is, change it to allowed. You can sort by directory to make it easier to find, not sure what the description name will be for it.
If you don’t see it in either list, right click on the inbound/outbound tabs on the left and add a new rule in each of them to allow the exe through.
If you need further help or picture diagrams of how to do it, let me know.