I’m sorry to hear you’ve been having some issues with your phone and the Monzo app. I wonder if it’s part of a wider set of issues with the new IOS. This is because I’ve had a bizzare few days with my new 
14 pro where iOS 16 was broken in a way that I (and all the Genius Bar staff in Edinburgh 
Store have never seen before… although I’m sceptical).
For those who may be interested:
The screen freezes: kicks all your apps out of folders…. home screen gets stuck behind the App library menu to the right and the widget menu to the left. Dynamic island would constantly freeze: and the software update page would display a can’t connect to server error…. The behaviour is similar to how a computer behaves when infected with malware/virus.
All in a terrible experience (screen recordings available upon request).The good news is that the Monzo app worked fine when it would open…
The explanation offered by 
technician was that an app that wasnt patched to run on current iOS build could have this effect but that a rogue app is the more likely cause ( this was offered in response to my suggestion that IOS 16 may be unstable)
The solution: I was given a new phone patched by the apple technicians who insisted that I set it up as a new device then manually install apps. I was advised not to restore the device using any of my backups from iCloud. …. I’m hoping apple release an update soon.
Note:
i’ve included a screenshot below from screen recording illustrating how the home screen gets mangled into the menus.
