I have an 11 speed 10-42 XD cassette that I am trying to fit on an XDR driver (this one - https://www.alltricks.com/F-41493-pieces-roues/P-676097-fulcrum_body_sram_xdr). No matter how I turn the cassette it seems like the splines on the driver are too big to fit in the recesses within the cassette. It's not even that it's stiff to push in all the way; I cannot get it on at all. It's like they're not even supposed to be compatible.
I know this is supposed to work because there's an official SRAM video showing exactly what I want to do:(from 37 seconds and you can see the splines engage at 52 seconds).
Edit: I solved it. Turns out that the ease of fitting in that video must only occur when you have it on the wheel. My wheels haven't arrived yet so I was just trying to see if it would fit by hand. It does with a chain whip and cassette tool.