More MFD Drama

I recently bought an 2009 Prius with ~175K miles. There were a number of things that needed repairs, which I knew about before buying it: brakes, clockspring, 12v battery, and the MFD. The MFD side (mechanical) buttons all work, but the touch screen is unresponsive... except when on the map screen. If I touch the screen on the map screen the crosshairs will move downward, no matter where I touch. Otherwise the screen is receiving power and the display is coming up.

What I have done:

• Had the MFD serviced by AutoBeYours: The symptoms are exactly the same after I received the MFD back. AutoBeYours told me that they bench tested the unit and also tested it in a Prius. AutoBeYours seems to have a very good reputation, so I don't doubt that they did that testing. They suggested that I replace the 12v battery (which I did with an OEM from dealership). Unfortunately that didn't help.
• I checked for and found one blown fuses... but that didn't resolve the problem.
• I checked and reseated the MFD cable connections
• I tried accessing touch screen calibration but can't get past the initial diagnostic screen because you can't get to the touch screen calibration screen with a non-responsive touch screen.
• I checked for debris around the touchscreen bezel, and cleaned some minor dust with canned air.
• I checked for error codes (with OBD2 and phone app), but there are none.
• I replaced the cabin air filter and didn't see any signs of rodents (which I guess can be an issue)
• The clockspring was replaced while the MFD was being serviced at AutoBeYours

I am pulling out what little hair I have left trying to hunt this down. AutoBeYours says that I can send the unit back and they will re-check and repair if needed, but I want to make sure that I have done everything I can on my end before doing so. I am hoping someone might have a suggestion on what else I can check.

 

2009 with 7 buttons, so pretty sure it's OEM #: 8611047260C0