Decided to play some D2 after having a long pause from it, Downloaded, Fired it up, In DX11 mode it works perfectly, Switch to DX12 mode and the performance drops like a brick, No clue why.
Steps taken so far -
-All system drivers up to date i.e GPU, Motherboard etc...
-Windows fully up to date
-Verified the game install
-Tried with overclock and without an overclock
I thought it could possibly be an issue with Intels 12th Gen Alderlake so I applied the compatibility option in the bios which disables the e-cores, Still the same low performance in DX12, This is the only game I have performance issues with, All the Assassins Creed games work perfectly, Same with Ghost Recon etc....
Screenshots showing the performance difference, Metrics in the top left -