Unable to connect to Serviio server remotely

I have read many of the posts on this forum about remote connectivity problems but I still cannot solve mine. In the Serviio console I go to the remote tab and check the automatically configure your router and save and then the connectivity status gives two green arrows. If I then try to connect from my phone either with Servvigo or by entering the MediaBrowser address in my browser it conects, if I have Wifi turned on on the phone which is part of my home network. If Wifi is turned off and I am trying to connect through cellular signal (Verison) Serviigo and the web browser fail to connect. The phone browser will connect to other web addresses. I tried using a hot spot ( guest wifi at a Chick Fil a) and neither would connect to MediaBrowser. My router is a Xfinity xfi router which does not let you access the router through its web address, you have to us the Xfinity app. I have tried unchecking the automatic connectivity box and assigning the 2 port forwards in the app. When I check connectivity after doing this I have two green check marks but it still doesn't work. I have tried turning off my anti virus and fire wall (Norton). Didn't help. Access to Serviio is allowed in Norton firewall. Access is obviously being blocked somehow in the router but I don't know enough to figure it out.