Config : Amd RX 5700 founder edition at default clocks speed, Ryzen 7 2700 at default clock speed, 16 gb of ram of DDR4 3200 mhz in dual channel at stock speed and a Corsair VS 550 watt 80+ power supply.
So i've recently experienced a few issues while gaming, in league of legends's client i'm getting like 5 to 10 frames per second in champion select but in game it's absolutely fine i'm getting my usual 400 fps or so and 300 fps in fights, however in some demanding titles like call of duty black ops cold war, call of duty warzone or hitman 3, i'm getting 1 or 2 frames per second in the menus and in game as well.
Also the temperatures are kind of all over the place, when i power up my PC my graphic card register 35 Degrees °C in afterburner and in radeon software until i launch any applications or games.
However in game i'm at 70/80 Degrees °C, but when i close any game the themperature does not drop at all it stays around 80 or even 90 Degrees °C, the temperature would never drop even when idle in my desktop for 30 min.
I took my graphic card apart, cleaning the inside and replacing the thermal paste that was burnt by the way, but the issue is still there after all that effort, i didn't see any broken stuff or broken pads on the inside of my graphic card so i don't understand where does the problem comes from.
i tried unninstalling and reinstalling the drivers with Display Driver Unninstaller (DDU) (i tried the lastest driver and a 2019 one) but with no success.
Here is 2 screenshots of my temps while idle in °C :