Hello,
When I play Fortnite and some other games, my GPU usage and my GPU core clock drop at the same time, I updated my drivers, Windows is up to date, I changed the settings high performance power supply, optimize the settings on all my games, disassemble and reassemble my graphic card but nothing changes, the temperatures are normal.
CPU : Ryzen 7 5700 X
GPU : RX 6800
Mother board : Asus prime B 550 Plus
SSD : MSI M450 1 TB
RAM : 2 x 8 Go