I sometimes start working on a midi song on Garageband on an IOS device and then export it to my Mac using airdrop. I then open it on my Mac, which seems to automatically generate a converted version of the IOS file, and continue to work on it in Garageband for Mac. I haven't had any issues with doing this until today, when all of the songs on my Mac which initially started as IOS files developed an issue where all of the midi notes have a permanent sustain effect on them. These songs worked perfectly on Mac before today. My IOS Garageband is still working normally. Songs that I initially created on Mac were not affected and still play normally. As far as I can tell, the sustain effect is not the result of the controller feature in any way, as it persists both when the sustain controller is set to 0 and in midi regions with no sustain controller in use. New notes that I make in the affected files have no sustain effect, but all of the notes that were there before today (both added on IOS and added on Mac after I transferred the files), do have a sustain effect.
My theory is that my converted files from IOS to Mac were all affected in some way that changed the code of each midi note within them to have a sustain effect. Is there any way I can remove the sustain effect from the notes?