Sound only plays on some trials and not others

Description of the problem: In our experiment we use a sound to cue participants to an upcoming visual stimulus. On most trials the sound plays correctly. On other trials the sound does not play. I cannot identify a pattern for the playing or not playing of the sound, it seems random. How can we solve this.

Here is the experiment URL:

I think this is a link to the code on the gitlab for this experiment.

Please let me know if it does not provide access to see the code and how I might provide that. Because the sound plays on some but not all trials, this seems like a code bug. Thanks for your help.

Could you share the GitLab repo of your experiment? This page explains how. My username is: tpronk

Thanks Thomas.

I set the project visibility in general settings to public.

Here is the gitlab link,

Let me know what else you might need. Your help is greatly appreciated! We feel so close to running this experiment online, which has been a long time coming.