I haven’t come across this problem before, but it could be a problem with advmame 3.5 handling of audio output device.
It might be worth reverting to regular audio temporarily, and seeing if advmame 3.5 works over the Pi’s built-in 3.5mm jack (assuming you’re not using a Pi Zero).
You can do this by commenting out the line: “dtoverlay=hifiberry-dac” in
And making sure the line
dtparam=audio=on is present and uncommented.