I had a similar problem -- the "pairs and connects fine but then fails later" sounds very much like https://bugs.archlinux.org/task/68346, which is now fixed!

fwiw, I personally got around this by using JACK (netjack server outside the VM, netjack client inside the VM). Somewhat fiddly to set up, but works flawlessly once it's running!

Derp, looks like the URL didn't get added properly; I've resubmitted as https://news.ycombinator.com/edit?id=21037750 - thanks for pointing it out!

You've pointed me at an edit link there, which is not a good thing to do.

But it works, I'll go have a look.