Finally FOUND THE SOLUTION (at least for me)
1. Completely close Steam and SteamVR.
2. Navigate to each path and delete the following files:
a. C:\Program Files (x86)\Steam\steamapps\common\SteamVR\resources\settings\default.vrsettings
b. C:\Program Files (x86)\Steam\config\steamvr.vrsettings
c. C:\Program Files (x86)\Steam\config\lighthouse\lighthousedb.json
!!!!!!!!!!!!!!BEFORE NEXT STEP MAKE SURE TO BACKUP YOUR "INPUT" FOLDER OR YOU WILL LOSE YOUR KEYBINDINGS SETUP!!!!!!!!!!!!
3) delete DCS files
C:\Users<user name>\Saved Games\DCS
Done this I started DCS but the menu was stuck (inside the VR moving the head the menu moves with the view)
, so ensure you have Steam VR STABLE VERSION, NOT BETA (mine was in beta) then add your DCS standalone to your steam library (dunno if it changes something but i did).
Launch DCS.
It works.
Hope it works even for you becouse it was driving me mad.
HUGE THX TO MY FRIEND PIANGE THAT FOUND THIS SOLUTION, ALL CREDITS TO HIM.