Hi @iambehindongpus
What is the wattage of the PSU in the PC?
The RX550 minimum PSU specs are 250W and for the RX580 it is 450W.
If the PC PSU isn't near the minimum required for the RX580 then you may have some problems especially when gaming due to the increased power required.
If the PSU specs are sufficient for the RX580 and it still doesn't work and the RX550 is OK, then most likely there's a problem on the RX580 GPU card. Are both the fans working on the RX580 card?