Breakdown in bluetooth media data transmission - data is delayed by one song

[Pillendreher]

Using Shuttle 2 to listen to music via bluetooth over my car's audio system, I've noticed a weird issue: For the last couple of months, the first couple of songs (I think it's 6 to be exact) are played without an issue. Yet, after the 6th song, the media data starts lagging behind by exactly one song.

So it goes (left is S2, right is my car)

Track 1 => Track 1 Track 2 => Track 2 Track 3 => Track 3 Track 4 => Track 4 Track 5 => Track 5 Track 6 => Track 6 Track 7 => Track 6 Track 8 => Track7

And so on. This keeps happening to whatever playlist I choose to play. The whole process restarts once I start a new current waitlist, ie switching albums helps for the first 6 song and then we're back to the delayed track data.