Probably a stupid question but did you check the notification settings on your device and in the app itself to make sure nothing changed when you downloaded the latest release? I’m assuming you did but if not that would be something to check out. If the update itself is the problem don’t look for a fix anytime soon. <Edited>. It’s really a shame because this is a great app when it works the way it’s supposed to.
Comcast did do an update to Pop settings earlier this year. Did you make those changes outlined here: https://forums.xfinity.com/t5/Internet/ANSWERED-Update-Your-Xfinity-Email-POP-Port-Settings/ta-p/317...?