Won't recognize instrument (midi channel) from xml file.

I added a violin part to a hymn, but it sounds like a piano. This is the muse file: https://musescore.com/user/30117598/scores/6457320
and I have attached the xml file.

Still a newbe on the low and flat part of the learning curve. What do I need to be looking at in the future for this type of problem?

TIA