It got me in a rather strange way. BIAB was playing fine through my focusrite device. But I invoked the "song" wizard from an .mp3 to get tempo and a chord chart. Hit play and NO sound. BIAB ok, wizard dead audio. While on the phone with pgmusic support, they asked me to check my playback device. Sure enough, default Win10 sound card had become internal el cheapo card.

It might be consider a "bug". BIAB was still locked into focusrite, but wizard went to win10 default. But then again, hey Microsoft, pretty sloppy update actions to change settings without permission.