Help! Song has turned into a minimal club remix!

Hi everyone.
Hard to even describe, but here goes. This morning, opened a Cubase 9 track I’ve been building all week. Lots of vocals, drum machines, hardware synths, basses, etc. Strangely, this morning, though everything LOOKS normal… when I press play, all I can hear is 1 vocal, the kick drum, and one bass track. That’s it. Everything else is silent.

Nothing is solo’d. Nothing is muted. I can detect no suspicious commonality among the 3 working tracks. Likewise, I can detect no commonality among the 20 or so that are not (no corrupt plugin, for example).

All tracks – playing and not playing – are set to Stereo Out.

I haven’t moved any folders or anything since last opening the project. I hadn’t even actually shut down Cubase.

So this morning, I have tried restarting Cubase. Restarted my computer (Macbook Pro). Restarted my audio interface (Focusrite 18i20). Switched audio out channels. Started in safe mode and temporarily disabled preferences. Tried running it through Built-in Audio (vs my normal outputs). And I haven’t made a lick of progress.

Any ideas!? Thanks everyone!
– Paul

This thread seems to discuss a similar symptom, w. no real solution. I’m not using the channel strip they mention, btw.
https://www.steinberg.net/forums/viewtopic.php?t=105983

SOLVED. A plugin on a single track. Beats the crap out of me. I just went through and deleted each and every one. And eventually one did it.