Certain banking apps use a buggy anti-tampering library which was broken by a security improvement in the most recent GrapheneOS release. It wasn't reported during 2 days of Alpha/Beta testing. We've paused rolling it out to the Stable channel and we're working on resolving it.

Compatibility issue is caused by these apps having hand-written 64-bit ARM assembly code that's making system calls with the 32-bit ARM compatibility layer even on devices unable to run 32-bit ARM code at a CPU level. They depend on a quirk of how 32-bit ARM compatibility works.

Unfortunately, it means we need to temporarily revert the removal of the kernel's 32-bit compatibility layer on devices without 32-bit support. Banking apps are holding back security with their anti-tampering libraries. They do this to make it harder to audit their insecure apps.