I have the same problem. 5600G, RX 6700XT and MSI 550 Pro MB. Spent hours on that... It would make the internal sound card pop and crack and if I used my external sound card, I would get a BSOD after login. Initially thought it was the external sound card's "older" drivers and bought a new expensive one for nothing.
When I used the integrated graphics (removed the 6700XT), everything was fine.
Only solution I found is also PCIe x8 for the GPU. I thought my chip had a hardware problem but I saw multiple posts with the same problem. Maybe we all got bad a bad CPU...
Did you ask AMD? I want to try a RMA but I don't know if I'm not gonna get the same problem with a new CPU (would make me lose even more time on this).