$ sudo apt install shim-signed=1.50+15.4-0ubuntu7 ... from proposed packages, followed by a reboot with secure boot enabled has the same result, stuck on UEFI vendor firmware logo.
Trying to capture additional logging for you next.
$ sudo apt install shim-signed= 1.50+15. 4-0ubuntu7
... from proposed packages, followed by a reboot with secure boot enabled has the same result, stuck on UEFI vendor firmware logo.
Trying to capture additional logging for you next.