strange try reflash modified bios, reboot, turn Off the PC, reset BIOS by a jumper, then enter into the BIOS and load Optimal Defaults settings, Save&Exit, boot to Windows and check SLIC again
@Serg008 unfortunately I was wrong, even though slic is showing as dell 2.6, for some reason I still get error 0xC004F059 when using OEM SLP key to activate server 2019 or 2022. The error seems to indicate invalid licence in the bios
No luck I'm afraid, I even tried downgrading to A1 then modified A3. Xsdt still shows alaska. There actually is no specific setting to disable windows 11 compatibility. I've disabled TPM & secure boot to see if that works but no go. I guess the last thing I could try is change from uefi to csm but I don't think that should cause a difference. No luck with csm either
Last times this issue has often occurred with motherboards that have BIOS adapted for Win 11. It seems that some BIOS settings (default values) prohibit changing the XSDT table name.