As far as i know you will end up with either a negative amp or negative voltage when you measure like that. I’m often measuring charging of motorcycle batteries, and are always getting negative amps.
But as the values are the same i don’t care. Thought about running all values through abs() to get absolute (positive) values, but that would be wrong. The way the Mooshimeter is made and the way you have to connect it to measure both amps and voltage at the same time will simply give a negative.
But. It would be relatively trivial to create a filter for uploading logs and get only abs() values. Even if that would be … well … wrong.