Wnat made it so confusing is I have two tetras. And I have tried everything possible to determine if it was a midi loop. However, this tetra is was really weird. I could not edit combos from it, because it would not display the voice name. Also, I could not edit the B part. So I upgraded the OS. Then, while it was attached to the mixer, the cable was pulled very hard when someone decided to visit me. So, I was convinced the cable had broke the solder or something. I put OS 1.5 back on but still, acting weird.
I thought I had ruled out for certain that it was not a midi loop. Surely the other tetra would lock up too, but that was just fine. I moved it to other keyboard not connected to any loop. I turn it off and on. Don't know, it can make you go crazy. It is very old and I don't even know if they would repair it now, or if it even needs repairs or I am just doing something wrong see.