No audio when Articulate Presenter '13 presentations uploaded to Canvas

Community Participant

I have never had this problem prior to this semester. I create my presentations in Articulate (still using Presenter '13 on a Windows 10 machine with Powerpoint 2016) for web delivery and upload the zip file into Canvas.  I then direct students to the presentation_html5.html file and the presentation loads but there is no audio!  The presentation works fine when loaded in a browser from my hard drive, and even when its uploaded onto another server and launched from there.  So something in the upload and expanding into Canvas is messing up the linkages to audio in the presentation.   I have done this for years with few issues, but suddenly this semester audio has stopped playing in Presenter presentations on Canvas! Please HELP!