That sounds exactly like how the synth effects work for me on the Zoom MS60B. Which IMO makes them unusable and turns me off from the BMS.Spent a little more time with it last night. I would revise my earlier statement a bit. I think it tracks the pitch really well. I think the attack triggering can get glitchy on quick runs. Whether or not that matters depends on the synth type. Some laser-beamy type synth sounds, you really need that attack to trigger when you hit the note.
I do still think it's related to holding a note and hitting a new one. It doesn't seem to happen when there's clear clean separation between the notes. It actually sounds kinda like an real monosynth if you hold the last note when you hit the next one. But...it doesn't behave consistently...or maybe it's more fair to say that it behaves consistently, but I don't play consistently? A compressor might even it out, dunno. Sometimes it will retrigger the attack and sometimes it won't. And I think it has to do with whether the last note is still ringing louder than the sensitivity? Or maybe whether or not your new attack is louder than the last one? I don't know exactly.
Compressor never helped my Zoom and I play very consistently, I think effects just struggle to track a bass, it's almost like the notes are harder for digital devices to catch.
I'm still gonna wait to hear more things but in general I hate effects that are inconsistent, same with basses. I've sold plenty of both based entirely on their unpredictability.