Fixed FPS issue

What I expected to happen was...:
The FPS stay like I ordered to stay, like 80 FPS, since my screen updates at maximum that framerate

What actually happened was...:
The game starts normal, but when I stay much time in the game, or I just start the game, it resolves to drop to the 30 FPS and the only solution for a while it is close and open the game, or who know use the Windows key (or similar) to unbug by "closing" and opening the window game

Steps to Reproduce:
1. Open the game normally at the fullscreen
2. Play it (for a considerable time)
3. After that, probably you'll notice the fluidity will down 

Attachment:

https://drive.google.com/drive/folders/1rwDSDDC-C9xHCySRsewxXXZnLAHQnUGQ?usp=sharing