Chord gets buggy over time

When using the chord block, it starts performing pitches outside the key over time.

This is what I've observed:

The first performance seems to be accurate every time.
Over time, the chord block performs notes that aren't specified.
I suspect it may be picking up something residual from a combination of 1) set key/mode 2) the chords that take us outside of a scale (e.g. major, minor, etc). That being said, my ear is telling me (listening to the video copied below) that the second performance seems to have doubled unisons of every pitch of the chord for the first chord (even though it doesn't have any notes that are outside the chord).

The subsequent performances of the chord block should be the same as its first performance, which is correct.

I don't see anything special in the logs.

sugarlabs / musicblocks