Sculpture glitches in Logic Pro X

I have just upgraded to Logic Pro X (10.2.0) on Yosemite after having used an older version on Snow Leopard. I am having a number of problems with the new version of Logic, including one in Sculpture where certain notes glitch out (not in a good way) while playing. For instance, I have a tubular-bell like sound based on the "tubular materials" preset. Most of the notes have nice sustained bell-like tones, but one of them (B3) just makes a short "squick" sound and the animation of the string vibration jumps briefly to vertical lines like a bar code. It does this very consistently with the one note, though if the velocity is below 50 it is OK. All the other notes play normally.

If I move the note up and down to other notes in the piano roll, then when I bring it back to B3 it will work again briefly, but as soon as I start playing the song, that note glitches out again.

I got a screen recording and grabbed the string animation during the glitch. (since I can't upload a movie).