This [Title Edited: "Personal Information"]

Can't get my email thru Xfinity app

They broke it, and don't seem inclined to fix it. See https://forums.xfinity.com/conversations/email/no-emails-are-displayed-when-i-use-the-xfinity-app-on-my-android-phone/6a4144c6dae469435211d24d. 

Quoting myself from that thread:

the solution is the one posted ... by @XfinityJustinM: 

• We recommend choosing your favorite web browser and bookmarking https://connect.xfinity.com/appsuite/ for your comcast email

Set up a shortcut to connect.xfinity.com in a convenient place and be ONE TAP AWAY from the email site.