found this on the product page for the Intel Wifi 6 kit.
https://www.newegg.com/global/in-en/intel-wi-fi-6-ax200/p/N82E16833106102
for AX200: Your PC will need an open M.2 slot (key E for Wi-Fi) on your motherboard. This product is supported by Intel® Core™ 8th, 9th and 10th gen processors.
if only key 'E' is needed, then it makes the connector having only the 'E' key compatible with
9560
9260
AX200
AX201
and so on...
what it boils down to is the CNVI support, AX201 with CNVI2 is not backward compatible with CNVI (strange).
and CNVI and CNVI2 support is based on the chipset.
had a look at the data-sheets of C200 and C400 and their CNVI implementation. It gives an overall description of the signals and Pins to use. It does not discuss stuff in detail but here is what I have for observations:
400 chipset has 1 additional signal than the C300 chipsets and renames 3 non-CNVi to CNVi pins and adds one more, this usually should mean that the functionality is changing.
These pins do not have any CNVi functionality in the 300 series chipset, and control bluetooth through a I2S bus. but now are included as part of CNVi Pins.
my guess is the newer CNVio2 devices (AX201) are expecting a different signal/protocol on these pins with the same layout on the connector and hence resulting in no-POST.
instead of adding pins with versions as we see in PCI-E, here we see a repurpose of the existing signals, its a revamp of the protocol rather than a upgrade. of course it is going to break things. like the moving from DVD to Blu-ray, you would need to buy a blu-ray player to use that.
is this fixable with a BIOS update?
depends on what has changed into CNVio2, if the changes depend on the facilities provided by the newer CPU and the chipset then it might not be possible. Like the blu-ray.