Sampler: not triggering all notes as expected

[xribene]

Describe the bug

I'm making an arpegiator, where the user plays a midi note, and this triggers a series of triggerAttack and triggerRelease events to be played later in time. The problem I'm experiencing is that a triggerRelease of a note N at timestep T, prevents any triggerAttacks of the same note at later time >T.
This happens only when I'm using a Sampler. However when I replaced the Sampler with a Polysynth that problem was fixed.

To Reproduce

I made a jsfiddle that demonstrates both the expected (right button) and the problematic behavior (left button).

Expected behavior
When clicking the left button, note "A4" should sound for 0.5sec, while "E5" and "C5" should sound indefinitely.