I have read https://grapheneos.org/usage#banking-apps
Currently most banking apps are working partially or fully but with how google planing to ban unverified sideloading, "get this app from google play", removing unlock bootlocker option etc.
We can guess that banks could implement more robust checks, which could make app unable to work for "our safety".
Currently there is no method for bypassing checks in grapheneOS.
Would there be a bypassing method in the future?