Question RX 570 throtteling while CPU usage

Jun 20, 2021
I Have a rx 570 xfx and a ryzen 5 3600x.
Just formated the pc, while in game the GPU started throtelling, 100% to 0%and the game started Lagging, It felt like the GPU was turnig on and off.
Downloaded a stress test. The gpu stress test was fine, 100 % all the time, but when I ran the CPU stress with the GPU stess test, thats when the GPU started dropping.
I´ve dissambled everything and cleaned everything, same thing.

Last year I had a problem with my power suply, the cable from the gpu melted and was shutting down when the GPU was requested. I´m assuming that maybe is the power suply again. They reapaired and sended back to me. Going to test with another power suply that i have here.
Anyway, maybe that´s not it and I need someone´s help, I need my pc to work also. I´m going to try and fix it. If I can´t I will have to send to someone.

Sorry for the mispelled words.
Mother board is stell legend b450 and I have hyperx 16gb ram.
power suply is 800 watts bronze plus