Such work will tax and overtax most systems. Try without the background music and dropping the bit rates. I see nothing wrong here. You are just hitting limits in your PC.
Again, there are a lot of new folk getting into this and they didn't expect the Spanish Inquisition. No I meant they expected everything to work without troubles or limits.
I have recently started recording my games using Game Bar in Windows 10. However the sound seems to cut out multiple times for only instances. It is not noticeable in most games but if I have background music enabled then it is noticeable. The audio records at 192 kbps according to Game DVR in settings