It's not even a problem of the LFO starting at the right time, it's that it doesn't maintain where it starts. If the LFO of the Tremolo has the volume up on say beat 2 and you leave it on, it'll drift from beat 2 to beat 3 to beat 4 and 1 and back around to 2 if given enough time.
Was it via a midi cable? It may be jitter, which I hope not, but the other device listening to the source (which is a Circuit Tracks) is an MC101, and it seems to be fine. That said, maybe the 101 is really accepting, I'll have to do some experiments, because my RC202 can't take jitter from the Circuit Tracks. That said, I've asked people more knowledgeable than me if the Tracks has jitter, and I've gotten that *if* it does, it's .1, maybe .2 off.