MIDI output is overriding my chosen sounds/instruments. Please help

Hi there,
*disclaimer: I'm pretty inexperienced when it comes to music technology. I could have easily missed something simple so all advice is welcome.

I have made a five instrument score and I am trying to send the midi to my keyboard to get a playback with new sounds/instruments. I am using the keyboard's in-built sequencer to see and modify the sounds/instruments set up for each midi channel. The midi is apparently being sent correctly but it is setting each midi channel to some specific sound from my keyboards sound banks. e.g. "Strings: #039 C-Berlin Strings 1" rather than the sounds I had prepared on those channels. It's not going to the keyboard defaults and it went to the same sounds when I restarted both the keyboard and Muse Score. I tried exporting the MIDI to a DAW but the same phenomena occurred, going to the same sounds so I assume that this is coming from data being sent with the MIDI file.

Is there a way to disable this or tell it to listen to the Keyboard/Sequencer instruments rather than the ones from the score on MuseScore?