sound like a defect cpu OR you have maybe bent a pin.
try to rebuild the pc from scratch:
cooler out, CPU out and everything back in
also possible is that you have now mounted your cpu cooler with to much pressure - so that mobo or cpu are damaged now
PC: R7 2700X @PBO + RX 580 4G (1500MHz/2000MHz CL16) + 32G DDR4-3200CL14 + 144hz 1ms FS P + 75hz 1ms FS
Laptop: R5 2500U @30W + RX 560X (1400MHz/1500MHz) + 16G DDR4-2400CL16 + 120Hz 3ms FS