Can confirm that it is working for me using the latest BIOS update and latest AMD drivers - no more lockups,  Fingers crossed it keeps working! I did take the advice to disable automatic future BIOS updates :/.
This morning I accepted a suggested update from Dell update tool: OS RecoveryIn the afternoon I have installed the latest bios version 2.11.0 and now my machine has become totally unreliable and unstable. It hangs during boots and in Windows. Thank you Dell for ruining my system once again  Already suffered from the NVIDIA lockups and thought I left the issues behind with switching to an AMD graphics card and now I've got an unusable system once more. Are more people experiencing similar problems?
XPS 8940, bios 2.11.0