stream on Roku TV while away from home

I installed the Xfinity App on my RV's Roku TV.  The Xfinity app works perfectly as long as I am connected to my home wifi.  When we travel and connect to either my phone's hot spot or campground's wifi I am unable to use the Xfinity app.  I receive an error message stating that I am not on my home network.

I thought my service allowed me to stream Xfinity anywhere.