It looks like the 3.0 software went back to having issues that the Mixing Driver was supposed to fix (I think). I just updated to v3 after not having used the US for a few months. I was happy to see that updates are still coming, but I'm less pleased that those updates seemingly break more than they fix. The old Mixing Driver has always been a bit of a hassle, but at least it allowed for ASIO and other (Windows) audio protocols to be used at the same time (most of the time). Just recently I helped a beginner setup their Behringer interface and they also ran into trouble playing ASIO and other audio. Myself being used to things like that just working, I gave them the appropriate advice and added "usually when I have that problem, it means I did something wrong to begin with". Perhaps this time my mistake was buying a Tascam product. I will fiddle around more, install old versions, maybe something works. That said, it's always disheartening to see support for consumer products fall so far behind support for pro-tier gear.