I’m experiencing the same issue on my b450 mobo. The issue seems to be that the windows audio driver keeps changing causing massive stutters and pauses of the sim. I found somewhere a workaround where you can disable an auto detect option in WMR sound tab and use external headphones. I’m not at my pc now so can’t tell you the exact option.
I also found that using the front panel usb 3 input works best on my machine