alt Hacker NewsGraphene OS user here. Almost all of the apps I tried work fine. All the banking apps I use work. Have you tried reaching out to the app developer or the service and explaining what Graphene OS is and asking them to support it? I was able to persuade one app to do it.
[1] https://privsec.dev/posts/android/banking-applications-compa...
Problem is that all banks require a national centrale controlled service for login (BankID in Norway). And it is this service that I cannot get to work running GrapheneOS. It worked a couple of months ago, but not anymore. And all customer services and complaints are directed to your bank who 1) has no idea what i am talking about and 2) no control over BankID verification requirements.