This is a symptom seen when the ETCLink and RFU cables are plugged in reverse order. Both have female 6-Pin Female XLR connectors. On the Expression series the connectors are side by side, and on the Express they are split apart. It is easy to put them in the wrong place in the dark!
Trace the cable back to be sure it is controlling the correct item. If they are in the wrong connector, plug the cables into the correct location.
Once the console is behaving normally, save the show to disk and deep clear the console. Reload the show and things should be back to normal.