I put Mellowtron on the SD card and funnily enough, not all the instruments load their samples.
MKIIFlute or Brass for example do not load, where as if i load Cello, Cello plays fine.
Then if i load MKIIFlute again or Brass again, I still here Cello.
I don’t have that patch loaded on my Organelle at the moment but it may have something to do with the patch and files are using a mix of upper/lowercase letters in the filenames. @thetechnobear explains this well: