Hi guys, our favorite game was unplayable for me so I spend 4 hours of testing and searching about fps drop at full screen mode,and better fps on windowed mode I found a definitive solution. It's very easy to resolve and for me it isn't Rare fault instead of Microsoft (Windows) It hapeened after Windows updates,before that the game was running fine.
If you have such a problem you are probably using two or more monitors(or tv) plugged into your's pc/graphic card. (In my case It is standard monitor and turned off tv used only for movies)
The case is if you are playing in full screen mode the graphic card renders the image double, so you are getting 2x worse fps. In window mode its working normally that's why you get the right frames per secound.
To resolve the problem simply go to your nvidia control pannel-configuring multiple monitors-choose only one screen without duplicating and your game must run fine. Thats All :) and there is no such solution on the internet.
BTW: If someone from Rare is reading this,you owe me a free copy of the game :D (im using game pass) :P
Have a good day guys and see you at sea! :)
