What if you set SHIM_VERBOSE in firmware, using 'sudo mokutil --set-verbosity true' after booting with just grub?
There should be debug messages showing up on screen to tell what is going on in shim in this case, and having those will help in debugging the issue.
What if you set SHIM_VERBOSE in firmware, using 'sudo mokutil --set-verbosity true' after booting with just grub?
There should be debug messages showing up on screen to tell what is going on in shim in this case, and having those will help in debugging the issue.