Click sound during playback that can't be isolated

I have a logic session with 4 audio tracks, nothing too complicated. When I play it from the beginning, a click sound and a small but sudden jump in the volume appears in 3 of the tracks, at exactly the same time towards the end of their first note.

However, when isolating the moment when the click happens or when playing from just before it (during the note in which it occurs), there is nothing. But if I play from before the first note, I hear it again.

The source audio I bounced the tracks from also contains nothing, so it's not actually part of the audio. It feels like it could be some kind of memory or buffering thing, but it really is a simple session, so I'm unsure.

Any ideas? Happy to include more details if that would be helpful.