Balletrist They have resolved the issue. It was because they disabled native code debugging (it's on by default for compatibility reasons).
More info on this (it extends beyond banking apps): https://grapheneos.org/usage#banking-apps
Many of these apps have their own crude anti-tampering mechanisms trying to prevent inspecting or modifying the app in a weak attempt to hide their code and API from security researchers. GrapheneOS allows users to disable native code debugging via a toggle in Settings ➔ Security to improve the app sandbox and this can interfere with apps debugging their own code to add a barrier to analyzing the app. You should try enabling this again if you've disabled it and are encountering compatibility issues with these kinds of apps.