Note that harassing the maintainer won't fix Google's attestation servers, and only serves to burn out volunteers who build your ROM for free in their personal spare time.
People who do this generally assume Play Integrity is just a bug in the ROM or that the maintainer forgot to toggle a switch. But Google made server-side changes targeting non-RKP (Remote Key Provisioning) devices. As a result, we all are getting only Basic Integrity until someone figures out a better solution.
The same goes for:
There is literally nothing your ROM maintainer can do! 😫
Remote Key Provisioning (RKP) is Google's mechanism where device hardware fetches cryptographic certificates directly from Google servers. If a device isn't using valid RKP, Google refuses to grant Device Integrity.
Wait patiently, until the community comes up with a solution.