peter What do you mean by "close the window"? And what do you mean by "audio loss"?
Try to increase the audio buffer size.
My buffer size i already increased to 1024 and close the window is the SONG PROPERTIES window you open to set speed then you close it by tapping outside this window to get back to see the lyrics you are on once you adjusted your speed , this reminds me to point out again, it is a pain in the rear that this window covers your lyrics while performing and adjusting speed i pointed this out ages ago, it should cover your song list area which is less important while performing as lyrics screen should never be hidden by anything at any time of performance including hand controls nothing should block your view of lyrics when performing.
Now Audio loss i mean TOTAL LOSS OF SOUND as you return from the song properties window , shortly after the window disappears ST3 has a hernia as its struggles with the fact you have adjusted the speed it seems to do some sort of an adjustment and mutes the now playing audio.
I have noticed this numerous times recently while playing around at home but never reported it , i will try to maximise my buffer to the last setting and see if it helps but i never noticed this issue earlier on as the speed feature was introduced.
Good luck with this one , i wonder if others have noticed this or is it something to do with only my device.
To make it fail , play a song, go and change speed then close your song properties, also my song has been broken down in to loops just in case that has something to do with it.
This is on iPad with latest operating system and ST3 software.
Cheers Damir