Is there a maximum number of USB devices one can pass through at one time?

I have an 8port powered USB hub at my desk, and pass through ports as needed. (For usb drives, card readers, etc.)

I recently plugged in a bunch of stuff (num pad, spacemouse, wired keyboard, laser engraver, etc.) and think I’ve hit some passthrough ceiling.

My question is, is there some maximum number of usb passthrough devices per instance?