Thought I would post this in case it happens to someone else. I didn't notice a similar post here.

Symptom: Lift arm on my TC raised normally when I pulled joystick back. However, rather than going down when I pushed the joystick forward, it raised further, seeming to struggle. It would go down when I pulled out the lift arm by-pass, but repeat the problem as again tried normal operation. There were no error codes. The tractor engine also had a slightly different sound to it, feeling a little rough. The cooling fan came on, indicating a work load I did not expect. This was what lead me to the solution.

Solution: I had previously used the dump bed. I found the rocker switch lowering the dump bed had "stuck" as I was lowering it, activating whatever valves are activated to do that. When I freed the rocker switch to its normal position, everything immediately returned to normal. Yippee.