What’s you secure boot model configuration? Disabled, auto, or another value?
A message from Acidenthara team:
“…To continue using Apple Secure Boot with older operating systems one will need to specify j137 in the SecureBootModel parameter, yet this value will not work with macOS 12. Similarly to Apple Secure Boot, APFS driver verification requirements were also bumped to macOS 11 and newer, and thus require one to change MinDate and MinVersion in the APFS section if older macOS versions need to be launched”