Hello,
For security there are a number of toggles that must be set properly in concert for secure boot to be finally enabled. There is a tree structured logic, so particular toggles must be enabled, bios saved, then bios re-entered to set the next toggle in the tree properly. Sadly the exact tree logic is poorly communicated.
It is easiest to simply make adjustments by trial and error, trying one toggle at a time, then re-entering after saving and observing changes.
At last the following should be active:
Security chip enabled. Some versions of chip need to be in mode 2.0. Intel and AMD have security chips with different identification letters.
BIOS secure boot mode needs to be in USER mode.
BIOS security keys need to be Factory Keys enabled.
BIOS secure boot needs to be enabled.
BIOS secure boot needs to be ON.
As mentioned for Windows 11 to be able to save changes, enter from advanced startup tab inside control panel, with user having administrator status.
Let us know how it goes,
Usedtoberich