Thats a 3S hard case so it uses a special harness (for 3S, has an extra bullet coinnector) you mentioned from Protec. I'm guessing, but are you sure the 2 wires that plug into the lipo case are correct polarity wise? Otherwise, your symptoms sound like cells are just way out of balance cause thats typically what makes balancer work for a long time. This would be the 1st Orion that I've heard of with the cell voltages that far off. Makes me think the wiring is not correct.

Do you see all 3 cell voltages on the charger panel? When correctly connected, you'll be able to read the voltage on each cell. I guess the other potential issue is that there's something work inside the lipo with the balance wiring - usually a small circuit board that all this is wired to. Something could be wrong there, bad solder joint is usually prob if there is one.

If you connect the harness to your lipo, you should be able to read the 3 cell voltages off the plug that goes to the charger. Have you tried checking it that way with a dvm to see what the voltage spread is between the 3 cells??