GrapheneOS developers currently don't have access to devices with CameraX vendor extensions. There's a list of devices at developer.android.com/training/camer with a column showing CameraX vendor extension support. Some may only have the old API that's no longer used.
Quote Tweet
GrapheneOS Camera app version 11 released: github.com/GrapheneOS/Cam.
See the linked release notes for a summary of the improvements over the previous release and a link to the full changelog.
1
2
7

