Dell inspiron 15 7577 inconsistent gaming performance

[primogen]

The laptop sometimes gives 60 fps in battlefield 1 and sometimes slightly below 30 fps. Does the same in every game. Not sure what's wrong. This happens after I close and reopen the lid. When the laptop is underperforming, the fans barely work and temperature doesn't even go up. Can someone please help me with this?

 

[primogen]

I used DDU and reinstalled the gpu driver but nothing's changed.

 

[Dawn913]

How can I know if the laptop is using 60 fps or 30 fps? I also got a laptop with the same model.