15 R3, Poor Performance

Hi

I've had this laptop for about 2 and a half years. I've noticed recently when playing Modernware that the laptop is performing like I am getting 30 fps but I am getting 60 fps according to my fps display. 

I have played other FPS games like PUBG and Apex and exactly the same was happening. 

I have looked online for a solution but everything I have tried is yet to work. Updated windows, BIOS, enabled GPU performance in BIOS, changed battery setting for best performance etc.

Any help would be greatly appreciated as I am kind of lost what to try next.

Thanks