I have this exact same issue. I also noticed it after updating from 4.22 to 4.24, it remains in 4.25. Currently I have max channel count at 12 and am not using any sound cues with any branches at all (just single wavs). The issue crops in over time, after about 5 minutes of play the background music starts cutting in and out and by 8 minutes or so of play the audio cuts out nearly entirely. Even when background music is the only audio it doesnt hardly play at all.
Background audio is priority 1 and all other sounds 0
I have not touched concurrency settings yet
All audio is 2d (not spatial), there is rarely more then 3 wavs played at once. After about 8 minutes of play background music (without any other sounds playing) has cut out nearly entirely.
frame rate stays above 45, audio cut out does not appear to effect frame rate or vice versa