Missing images and mp3s in course presentation on WordPress

I am using course presentation in a Wordpress environment. Sometimes using the drag and drop module, sometimes the image one.

After creating a presentation and looking at it everything seems in order. However, often when I check on it a day or two later it has missing images and audio files. I look on the server and the images are indeed not in the folder of the activityID. I have not detected a timeframe or why this happens. 

I am attaching a screenshot and a link to such activity.

http://www.clemontreal.org/fr/exercice-h5p/le-son-e-avec-la-lettre-e-eco...

I have others I created last year but I did not use presentation for any of them and all images are still there. But I do not know if its really link to the presentation, my server (web costing canada) or the H5P plugin. 

If anyone has suggestions or solutions please share, I have a total of 120 of tehse to make and so far I have had about 10/30 with this issue.

Thank you!