The Matilde Tracker is monophonic

[user]

A note that is played in Matilde Tracker will kill an already playing note, even though if it is a different instrument. See test case.

[user]

Test case. Fail if silent, pass if it plays a beep.

[user]

It's not monophonic. Play both samples in a single pattern, just add another track to it (ctrl +) for the second sample and so on. (In your example file, both samples are in the same channel (even if in different patterns) and that's why one sample out-turns another.)