Well there might be more than one issue here. It won't be the max size though.
The first issue is that you have two audio players showing up, for one file. In this case only one player will work, if at all
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The appearance of two players is caused by "double filtering." The link to the media file, is parsed by both the multimedia plugins filter and the PoodLL filter, so both try to turn it into a player.
In most, but not all, cases moving the PoodLL filter higher in the list of filters than the Multi media plugins filter solves the problem. When it doesn't, usually because the media file is being used in a "label," disabling the file extension (mp3, or mp4 or whatever) on the multi media plugins filter (site admin->appearance->media embedding) will fix it. For PoodLL you can disable the file extension at site admin -> plugins -> poodll filter settings.
You could also turn either filter completely off which would solve it. But there are reasons to keep the multi media plugins filter. As an example, because it will turn links to YouTube videos into Youtube players.
You can record audio using the MP3 recorder in PoodLL, or via the older "audio recorder"/red5 recorder. The former transcodes to mp3 in the browser and uploads it. The latter records on the Red5 server , and Moodle copies it directly from there to itself. Depending on which method you are using the problem could have a different cause.
If you use the MP3 recorder, it doesn't work well with long recordings. Too few resources available in browser. 2-3 mins is the max. 50 seconds seems a bit short to cause a problem, but it might yet be the culprit.
If you use the red5 recorder, it could be a case of the server being overloaded. It happens. The Red5 server is set up to auto transcode to mp3 if the mp3 box is checked on the audio/red5 recorder (and you haven't configured FFMPEG on moodle). That can time out on long recordings.
For the most part those are the primary causes of failure. There are other things to look at. A sneaky one that could possibly be the culprit here, is Suhosin being activated on the Moodle server. That sets a max size for file uploads from browser (ie from the mp3 recorder) and they get stopped when they hit the limit. I have had it once or twice, but its not that common.
I hope all that helps.