MPG dash calculator broken after IPM replace

So back in January 2017 my 2012 Prius V died on the way to work, turned out to be a IPM failure which my neighborhood dealership fixed for free.

However since I got the car back, the dash readout for the MPG calculator is on crack. At first I thought I maybe just had to drive it for a while for it to calculate an average again, but here we are 4 months later and I just took a 1000+ mile road trip and it's still totally wonked out. It gives readings, but they're all over the map, sometimes just sitting at 99.9 for a few seconds, then jumping down to zero, then some other random number etc., and it never has an average at the end of a trip.

I've had the car 5 years, so I know it is not functioning correctly. I've never ever seen it say 99.9 or all zeros on there, and now it's part of the normal, constant, random number selection that seems to be happening. As far as I can tell it's the only thing being weird after that IPM replacement though. Is there any software reset I can do? Or do I need to take it back to the dealership?

Thanks in advance!

 

Yes, a 2012 Prius v Five. I made an appointment for Monday morning at the same Toyota service center that did the IPM fix, hopefully they'll take care of it.