The same issue has started for me, I'm showing anywhere between 0.1 mpg to 2,400 mpg. This software has been buggy from the start but, wow, it's totally useless now.
Now it's almost nine thousand miles per gallon showing. I emailed mobile support to see if they could provide an update on what's going on but I've only received an automated acknowledgment of my query so far.
Edited by GlennR, 29 January 2018 - 09:05 AM.