more midi export problems

When Exporting to MIDI, some elements don't export correctly. Multiple pitched percussion elements came through fine. The Piano came through as one file but when I add it to my DAW it becomes two events, one for treble one for bass clef. Not the worst problem, but the drumset and triangle lines aren't working for me at all. They don't load as MIDI files in S1, it's like its trying to open them as a whole new project. Tried with RPN and without. same result. I'm using this score as a backing track for a student so any help is appreciated.

OS: Windows 10 Version 2009 or later, Arch.: x86_64, MuseScore version (64-bit): 4.1.1-232071203, revision: e4d1ddf
Studio One 6.5.1.96553