Hey Calvin,
Can you explain what you mean by “I am now having difficulty getting the experiment working in an older version of PsychoPy again”. You will need to recreate the experiment in the newest version of psychopy to be able to run online experiments.
Do you have variable stop durations? As in, are the audio files all the same length? If not that will cause issues.
And refer to the crib sheet for how to fix possible issues with .wav ( PsychoPy Python to Javascript crib sheet 2023 - Google Docs ).
Try running through your experiment sequential, rather than random and see if it is a certain audio file that causes it. You state that it is variable in WHEN it occurs, but not any description as to if it’s linked to a specific audio file.
Issac