Aha! That would very likely be the issue then.
You might have some setting that makes apps per default prefer the integrated graphics.
Either change the Windows settings or change it in the Nvidia Control Panel;
Windows settings
1. Search for "Graphics settings" in search bar
2. Find your GameTranslate installation folder and select GameTranslate_Desktop.exe
3. Set it to use "High performance"
Let me know if that changes it to use the dedicated GPU & fixes the issue.
I have actually had the same issue before when I tried to use the app through a Virtual Machine, and it would default to using my integrated graphics. I did implement a fix for this in the code, but clearly Windows/Nvidia still overrides it sometimes. It is possible for me to make the app change some Registry keys to make it harder for it to be overridden, but I'd rather not do that for several good reasons.