Moodle Interactive Video loses sound after leaving and returning on Apple devices

Using Moodle 3.9 latest, videos are MP4 files generated by Adobe Media Encoder, h5p version 1.22.3

Interactive video content type stops playing audio under these conditions:

1. User is using Apple ipad or iphone. (not tested with Apple desktop computer)

2. User begins playing Interactive Video. User stops playing video.

3. User leaves Interactive Video page.

4. User returns to Interactive Video page and clicks play. Player now has no sound.

Has anyone else seen this symptom, or better yet, have a fix?

thanks.