Thanks for reaching out. I've been able to pull up your account & share with engineering to troubleshoot.
I have the same problem with the same two apps. It seems to work on the side of the apps. When I log into the nest app, it shows multiple permissions granted to the Xfinity Home App but the execution never completes (I have also tried several times)
GAKnutse & Jhieme20 --
Can you please confirm you are using the most up to date version of the Xfinity Home app (9.10)?