Comcast needs to address this problem with their phone app. For me, an iPhone user, the problem just started this month after years of successful use. I'm starting to wonder if the Xfinity Connect app has been left behind as Apple updated the iOS to 13.x. Others appear to be having similar problems with Andriod, etc. The ball is in Comcast's court. Don't blame us paying subscribers as you usually do. For what we are paying per month it should be perfect all the time. My Comcast bill is higher than all of my really necessary utilities (heat, electric, etc.) combined. And yet we get calls from Comcast salespeople wanting us to add more channels, speed, or whatever, to an already bloated system at an even greater cost. Just fix what we are paying for now!
My solution has been to use the always reliable FireFox web browser app with a bookmark to my Xfinity email page. When I close Firefox, I just leave it on that page so that every time I start it my email is ready to read. Honestly, I think this Firefox method is faster than the Xfinity Connect app ever was, even when it worked right.