Audio on website not playing fully - stops and repeats - audio

Question

I run a church website, where we upload the audio from each week's message. I have a few folks who are telling me that on the website, the audio file will play for a few minutes, but then it unexpectedly restarts to the beginning. They can't listen to any of the audio files from start to finish (they run 15-25 minutes). Any suggestions as to what could cause this issue?
The audio files are pushed to iTunes in a podcast, and no one has any trouble with the audio files playing in full on iTunes. The issue is only on the website.
I have not been able to replicate the issue on my computer, so at first I thought it was just one person's problem. However, I've had a few different people tell me they have encountered this problem. You're welcome to test the issue yourself - wsumc.com/multimedia-archive/broken-nation/
Thanks for any help!
<div class="audio-container">
<span class="mejs-offscreen">Audio Player</span>
<div id="mep_0" class="mejs-container wp-audio-shortcode mejs-audio mejs-hide-cues mejs-container-keyboard-inactive" tabindex="0" role="application" aria-label="Audio Player" style="width: 280px; height: 40px; min-width: 169px;">
<div class="mejs-inner">
<div class="mejs-mediaelement">
<mediaelementwrapper id="audio-8556-1"><audio class="wp-audio-shortcode" id="audio-8556-1_html5" preload="none" style="width: 100%; max-width: 100%; height: 100%;" src="http://wsumc.com/wp-content/uploads/Broken-Nation.mp3?_=1">http://wsumc.com/wp-content/uploads/Broken-Nation.mp3</audio></mediaelementwrapper></div>
<div class="mejs-layers">
<div class="mejs-poster mejs-layer" style="display: none; width: 100%; height: 100%;"></div></div>
<div class="mejs-controls">
<div class="mejs-button mejs-playpause-button mejs-play"><button type="button" aria-controls="mep_0" title="Play" aria-label="Play" tabindex="0"></button></div>
<div class="mejs-time mejs-currenttime-container" role="timer" aria-live="off"><span class="mejs-currenttime">00:00</span></div>
<div class="mejs-time-rail" style="width: 145px;">
<span class="mejs-time-total mejs-time-slider" role="slider" tabindex="0" aria-label="Time Slider" aria-valuemin="0" aria-valuemax="NaN" aria-valuenow="0" aria-valuetext="00:00">
<span class="mejs-time-buffering" style="display: none;"></span>
<span class="mejs-time-loaded"></span>
<span class="mejs-time-current"></span><span class="mejs-time-hovered no-hover"></span>
<span class="mejs-time-handle">
<span class="mejs-time-handle-content"></span></span>
<span class="mejs-time-float" style="display: none; left: 0px;">
<span class="mejs-time-float-current">00:00</span>
<span class="mejs-time-float-corner"></span></span></span></div>
<div class="mejs-time mejs-duration-container">
<span class="mejs-duration">00:00</span></div>
<div class="mejs-button mejs-volume-button mejs-mute">
<button type="button" aria-controls="mep_0" title="Mute" aria-label="Mute" tabindex="0"></button></div><a class="mejs-horizontal-volume-slider" href="javascript:void(0);" aria-label="Volume Slider" aria-valuemin="0" aria-valuemax="100" role="slider" style="display: block;">
<span class="mejs-offscreen">Use Up/Down Arrow keys to increase or decrease volume.</span><div class="mejs-horizontal-volume-total">
<div class="mejs-horizontal-volume-current" style="left: 0px; width: 100%;"></div>
<div class="mejs-horizontal-volume-handle" style="left: 100%;"></div></div></a></div></div></div></div>