Not sure if that's the URL you found but at https://docs.microsoft.com/en-us/microsoft-365/enterprise/urls-and-ip-address-ranges?view=o365-world... MSFT indeed lists *.skype.com TCP: 443, 80 as required
Would you be able to tell me what the URL that you had to white list was? I'm experiencing the same problem and our firewall logs are taking forever to filter down...
So I just created an account after resolving this issue. Hopefully it works for some of you guys out there..
My Solution for Teams:
If both devices are on the same subnet and you still can't pair them after logging into the tablet and polycom unit and if its still saying it can't find any device check your firewall to see if any in-bound or out-bound traffic is being blocked for Skype.Portals for both the tablet and polycom unit.
Make sure that both of your device have 'Skype.Portals' whitelisted.
*I've copied and pasted a screenshot to the body of the message and also attached the the same screenshot just in case the body image doesn't come over.*