Hi AR,
It looks like this doesn’t work well with Infinite Scroll turned on, so I’ve disabled that feature for you:
https://en.support.wordpress.com/infinite-scroll/
As a result, the audio players all work as expected.
Also just a heads-up that since your site has a Personal plan, you’re entitled to live-chat and email support, accessible here:
https://wordpress.com/help/contact
You’re welcome to still post in these forums, but those other support avenues may be faster, and you’ll always get a staff reply.