I've been using this AudioBox 1818VSL for almost seven years, and it's never given me trouble with using WDM audio channels to send Windows audio to the same output I'm using for ASIO while the ASIO driver is in use before. Even after the VSL software support was dropped and I began using Universal Control, I was still always able to use things like YouTube, SoundCloud, and Spotify concurrently with ASIO in Studio One. Windows 7, 8.1, and 10 have all performed similarly.
For some reason, and I can only assume after the recent Universal Control update (v22.214.171.124526 according to the About dialog), that's no longer possible. I just watched a 7-hour webcast replay through YouTube in Chrome, then after opening Studio One to map Control Link parameters with my iPad, I couldn't get YouTube to play audio anymore. Here's the details on what's happening:
Normally when there's an audio conflict in Windows, you just won't hear anything, and the software will eventually tell you it encountered an error while attempting to play audio. Instead, I've gotten the software to play audio for varying amounts of time, from a quarter second to a few minutes, after which point the audio from YouTube or Spotify will end, and either the video or the seek bar will continue running for a while, and finally the programs will report an error. This does not happen when using onboard audio; it's not the programs themselves. Changing the option to release the audio driver in the background in Studio One helps as long as I don't attempt to use Studio One again, or even put it in focus, because when I do, it engages the ASIO driver again, and the problem persists.
Even last week I didn't have this issue. I remember updating Universal Control on its own recommendation, which updates its supplied drivers, a couple days before coming upon this issue, and this is the first time I've had the DAW open since that update.
Of course, this isn't always a game-breaking problem, because I don't necessarily need to be able to play from other programs while Studio One is open, but I have used and intend to continue using Spotify for referencing, and having Windows audio available while ASIO is in use seems like sort of a basic feature, anyway.
What do I do? Can I downgrade Universal Control and its drivers to correct this problem? Or is this PreSonus telling me it's time to let the "VSL Experiment" die and buy something else?