Audio not playing on Mac, Safari version 12.0.3

We're running into a similar issue when testing in Safari (Version 14.0.3 (16610.4.3.1.4)) which we're not experiencing in other browsers. Course published using current build of SL360 (3.49.24347.0)

We get the play button on launch, and the course plays as expected. Then randomly on some slides, the audio file on the base layer just doesn't play on initial viewing. The audio will start playing if you click anywhere on screen and plays as expected on revisit. Other slides that are set-up exactly the same are working without an issue and I can't spot a difference in how the affected slides are set up compared to any of the other that work. I should also note that the affected slides are not the first slide to contain media in the course (previous slides that work also contain audio clips).

Slides are not set to auto-advance, so the user is required to click the next button.  Also, as we test the course, we're trying to replicate a typical user experience (linearly through in one sitting), so we're not pausing the content or jumping around using the menu.

Any thoughts on what might be causing this or a work-around would be greatly appreciated. Thanks!