gpu freezing

As I mentioned, the screen freezes when I start playing and the core clock is on factory settings, but the problem is solved when I lower the core clock to -200 MHz . I don't know why I have to lower the core clock from its base speed. I have been playing on the same factory settings in the past...

My PC freezes (sound is still there, when i'm on discord and there are people talking or even music playing, I can hear them, and I can still talk on my mic for a few seconds until I no longer can which I have to restart my pc) most of the time when my gpu usage reaches 99%. The gpu temps are...