When swiping a notification from Monzo about a new message, the app loads with a keyboard displayed but then gets stuck on the loading screen, you then need to force close the app and open it again, then go to chat.
Chat in general is fairly buggy for me, and tends not to update very quickly. Badges also show incorrectly for new messages, and sometimes doesn’t notify me at all.
I’m on an iPhone XS, running iOS 13 beta 6. Monzo app version 2.60.0 (551), installed via TestFlight.