I have tried everything, from Nvidia control panel checking High performance Video hardware in every single option available…til disabling built-in intel HD 3000 in device manager - control panel…
It seems that Halo Wars 2 only starts using intel HD.
On the other hand , Halo Wars Definitive edition is working properly and 1 month ago had the same problem ( I supossed 343-CA fixed it…)
Thanks for the support.