This is the official helpdesk of Spacial: https://support.spacial.com/hc/en-us/requests/new
It will probably take you a week of going through all the questions we asked again until you can convince them to take a deeper look at your problem, but they are the ones that can help you.
In these days, i got several times this kind of issues and I did solve converting the files from WAV to FLAC instead of to MP3.
I'm afraid to open a ticket with SpacialAudio.
Last time, I did open one in which I wanted to solve the fact that SAM several time freezes during the change of song.
They asked me for the config file that I sent, and they didn't came back ever since.
Now, I have here an MP3 ripped from a CD, that sounds great with every player but in SAM.
From the same CD I ripped the same songs but in WAV and converted in FLAC (44k1 24bit) with Audacity
The FLAC files are sounding great!
I'm very afraid SpacilAudio will ignore this and they will continue to deliver bad MP3 playing systems forever, as well as they neglected the ticket related the freezing moments ...
MP3s are sounding often like full of sand (high frequency spectrum) which is different than aliasing sound.
The "S"es are splitted among the channel .. it looks like a dirty vinyl ...
So: RED light to SAM's players