8L90 operating system problem

Hello guys. Interesting problem I'm having and I thought i'd ask here to see if anyone has had similar issues and what the fix was.

I've got a car with an unlocked TCU, the TCU was installed and programmed at the dealership for a 2018 C7 Corvette. The original operating system for the TCU was 24286913 but after the reprogramming/install the TCU now reads 24291281. This means, despite the TCU being unlocked, we're unable to read it at all. We figured we'd give it the old college try and did a "write entire" with a 24286913 map. The transmission "works", but the ECU throws a U0101 code and automatic mode doesn't work properly.

Going forward, does anyone have a 24291281 image/map I can reflash back on? And if we do manage to fix this with a GM MDI tool, how do we program this transmission now? Should I ask the dealership to simply install the 24286913 operating system? What are our options here? Does anyone have a GM MDI tool link they'd recommend?

For now we're just going to put the stock TCU back in the car.