Can't detect graphic card

I have a laptop with an adapter for external graphic card GTX 750 Ti 2GB. This allows me to play Skyrim or Witcher 2 or 3, but one game in a few can’t detect my external GPU and forces the integrated card to work, making so low FPS that it’s unplayable. That’s the case of Mutant Year Zero. I changed the settings of the game in NVDIA Control Panel, but with no result. Downloaded new drivers a few months ago. I would be grateful for any help.

Lenovo T410
Intel i-5
Windows 7 64 bit
External GPU: ZOTAC GTX 750 Ti 2GB