Audio is horrible every minute or so.

I am trying to listen to some music using my Bluetooth headphone.
Normally this works quite OK (modulo the usual BT lightning strokes that seem to never go completely away, but normally these are typically split seconds and "only" every minute or so.
But today, the music play is terrible! Every 10 seconds or so the music stutters, breaks away or it sounds like a big truck rushing through my room. It's terrible!

The only thing I could identify so far is that some process "Windows Driver Foundation - User-mode Driver Framework Host Process" seems to be permanently consuming 30+% CPU. What the heck is this?
Besides that the "Antimalware Service Executable" seems to steadily consume another 15%.

How can one "dampen" the resource hunger of such processes such that they leave media player and its driver do its business? I would expect these to be "background processes".

This is on a MS Surface Pro 4.