[Halloway]

Did you manage to recreate this one? Has anyone else had the same problem? 

I haven't, no. If you can identify the first of these builds with the issue it may point someone in the right direction.  

 I've started testing earlier builds but I've got a problem in that I can update to #0401 (in which the audio glitch is still evident.) but if I try to update to #0301, it won't reboot after installing. It just sits there with the big square rainbow. Am I missing something? 

Update: the earliest build I can install on my RPi3 B+ is #0310 and the glitch is evident in that build. I will try other avenues now, perhaps try the analogue audio output to see if that is problematic.