I have updated my Innerspace to 6420, created a new team (3 boxing). When I log in and check the settings all clients are running DX12 and not DX11 Legacy?

I tried the work around yesterday (d3d11legacy or something similar) and was running fine, after the Innerspace update this morning struggling to get 3 box team to work.

If the new Innerspace update 'forces' my clients to use DX11 Legacy, is there something overriding it setting it back to DX12 which I should be changing (within the game possibly)?