Two copies of an uploaded audio file

[vnicoletta]

Hello!
When replicating the second problem you described, I found the same to be true. However, I realized that the name of the file in the stimuli's "content" has to match exactly how the file name is written in Resource Files (including the cases of letters) to avoid this issue. 
For example, if your audio file is named "Sample.mp3" in Resource Files, then your stimuli would have to read:
{
  "type": "audio",
  "content": "Sample.mp3",
  "barrier": false,
  "visible": false
}

This will prevent the doubling of stimuli files in your Resource Files as well as allow the stimuli to pull the file straight from there. 
Hope this helps!
Best,
Victoria