adding *.exe files to antivirus exception (I use Nod32)
starting windows without additional software (Selective Startup)
Nothing from those experiments worked.
I Launched game from XboxGames\Warhammer 40,000- Darktide\Content\binaries\Darktide.exe and it works just fine, when rolled back to launching it via Launcher issue as described.
I hope this will allow gamers to start the game and fatshark to find the issue.