Create a new profile.
Install Google Play Services & Google Play Store in it.
Install Greenlight banking app in it.
Enable Exploit Compatibility Mode for Greenlight and disable Hardened Memory Allocator
Try using Greenlight. Grant any permissions it (or Google) asks for.
If it works, you can start pairing things back to find what the specific issue is.
If it doesn't work, the most likely explanation is that Greenlight implemented the Play Integrity API and GOS can't pass that because of Google's monopolistic business practices.