One of your two processor boards is acting up. I had Lexicon diagnose and fix this for me, in what was likely their last moments of doing that service.
They had me pull one board, or the other, and note which one misbehaved. You'd only get one machine, I think, or one set of outputs.
The dsp and routing are dynamically allocated, each time you power up or change machine format. So a 'dead' dsp module makes it's absence known in random places.
So, that might help narrow down the defective board, not sure how to go about getting it fixed...
With the bad board removed, the other machine will behave well, and there's less to ship.