This is an intermittent problem I’ve had for a long time, I thought it was fixed, but it wasn’t.
Going in and out of sample mode will randomly change/prevent the machine outputting audio to anywhere but headphones. The machine will play sequences and pads over the appropriate outputs just fine, but going into sample mode and back will intermittently change that to only outputting over headphones.
Sample monitoring is the same. You can jump back and forth between base and sample mode, and the ability to hear either sounds from the machine or sample monitoring over the expected outputs or headphones is completely random.
As you might expect, this almost completely destroys the ability to use the machine. I used to have this issue sampling and monitoring PC audio over USB as well as sampling from inputs 1 and 2, and sending audio through the mix outs. Now I have the same issue without any USB usage or mixouts, just the individual outs.
I took this quite poor video showing just the ability to get a pad to play going in and out of sample mode, hard thing to do with one hand needing to hit four different areas of the machine repeatedly.