Windows 11, it's doing my head in and I don't even have it.

[MrRadio]

Play the fanfare and beat the drums. It's here ... but my computer doesn't make the cut OR does it?
I have a 1 year old purpose built machine running W10 Pro 21H2. The Windows health check reports that I tick the box for all but one requirement, secure boot. The MB is
Manufacturer ASRock
Model H410M-HDV (CPUSocket)
Chipset Vendor Intel
Chipset Model Comet Lake
Chipset Revision 05
Southbridge Vendor Intel
Southbridge Model IDA3DA
Southbridge Revision 00

BIOS
Brand American Megatrends Inc.
Version L1.31
Date 1/04/2021
I have tried disabling CSM but the PC won't boot with it disabled so I have set the CSM sub sets to UEFI only and yes it boots but still fails the test on secure boot.
Having trolled through the UEFI setup for most of yesterday and part of today I am ready to throw my coffee cup at the screen. I don't think that will help though.
Interestingly , when I follow Windows instructions to access UEFI setup through its update and security -> recovery system UEFI isn't even shown. I updated the UEFI/BIOS today but nothing changed.
Are there any UEFI experts to suggest what I am not seeing with my 74 yr old eyes. I would be grateful for some help

EDIT: ASRock advertising claims this MB is W11 ready.