test mode

The latest Dev release will not allow me to enter test mode for driver development using the normal entry method. I am currently using:

Edition Windows 11 Pro Insider Preview Version 22H2 Installed on ‎9/‎25/‎2023

OS build 23550.1000 Experience Windows Feature Experience Pack 1000.23550.1000.0

I normally use a shell script in admin mode:

Bcdedit.exe -set TESTSIGNING ON

echo done

pause 3

it fails with: An error has occurred setting the element data. The value is protected by Secure Boot policy and cannot be modified or deleted.

I only have two options for secure boot:

Windows UEFI mode 

or

Other OS