I managed to get Kernel 5.6,5.8 and 5.9 Working with Qubes 4.1 (in fact I’m currently trying the bleeding edge 5.10.11-1 as I type this). As a note, for many experiencing LAN problems here, If you have a Realtex 8125 Ethernet card you need kernel 5.6 or above for it to work in qubes.
You will need to do this on a fresh Qubes install as far as I know.
See my answer on this Qubes Forum Post to get things working.