I am US-based. I have a handful of credit card apps, and a few banking / investment apps - all of them in my experience have worked fine. ONE of them required me to toggle a GrapheneOS option that enables you to exempt certain apps from some of Graphenes more hardened safety measures.

“Exploit Protection Compatibility Mode” is the toggle which can be flipped per-app, and is very easy to access so you can quickly troubleshoot whether that’s related to any app troubles or not.

Similar to the other comment, I also use Pixel Camera by downloading the Google pixel cam APK and installing. I’ve removed all permissions from the camera (and photos) app besides to the camera lense itself, and file permissions of course. You can even use Pixel Cam’s hefty features like unblur, erase me, etc. - though certain ones require you to temporarily give network access to the camera app so that it can reach out and download necessary packages. Once done, you can remove network permissions and the downloaded function will remain functional.