That started about Ner week ago always in the final match, no matter if r6 or Fortnite.
Driver not up to date?
Hardware defective?
What has changed in the last few days or what did you do before the problems started? Any programs installed?
I tried to update your drivers, I updated them, and then we went again
In the summer, your PC may overheat
Nothing done, I just screwed my PC. Lag probably overheating.
This can also have a cause… The PC should be dust-free.