Yes, it has to do with the 1% battery increments not working. The battery monitor widget (as well as circle battery widget) uses the same value as the 1% battery increments would. That value, for some reason still unknown to the devs, is returning a random number instead of the actual battery status. The rest of battery monitor widget will work, but not the part that shows your exact percentage.
if you go into settings->monitoring and turn off "1% increment support" you MAY get the 10% increments to display, but even that seems iffy. Circle Battery Widget, on the other hand, doesn't even display anything. (it adds a widget to your homescreen, but it's invisible because it only knows how to display values from 1-100.)