This also occurs on MusciBee v2.4 which I have installed alongside the most recent version of MusicBee. So this issue with wasapi or asio output has been around for a while. Once I changed to ASIO the difference was huge in terms of quality. So I have no intention of using the standard setting.
I do not have the knowledge or understanding of why this behavior happens. Is it something that can be fixed in the code or one of those hard to squash issues?