MIDI: Repeating MIDI Notes Blend Together

I'm trying to play several different MIDI sound clips. A couple of them sound just fine, but a few of them do not sound correct when played through either the simulator or device. The common issue I've seen happens when a MIDI file with several repeating notes gets blended together into a single note, instead of sounding like individual notes. I've opened up these MIDI tracks in Logic Pro and GarageBand to confirm that there is supposed to be a little "breathing room" between each note.

I'm using a square wave for the synth player, and then apply a copy of that to the tracks of the MIDI file. Should I be making any other additional modifications to the synth player or the sequence?

local snd <const> = playdate.sound
local synthPlayer = snd.synth.new(snd.kWaveSquare) 
local sound27 = snd.sequence.new('sounds/Sound27-Square.mid')

local track1 = sound27:getTrackAtIndex(1)
local track2 = sound27:getTrackAtIndex(2)

track1:setInstrument(synthPlayer:copy())
track2:setInstrument(synthPlayer:copy())

sound27:setTrackAtIndex(1, track1)
sound27:setTrackAtIndex(2, track2)

sound27:setTempo(120)
sound27:play()