Updated, but same issue. I've tried some more ranges and it seems like if you have just one step below zero, then it is ok. If you have two steps or more, it is stuck between the two lowest numbers.
E.g. if you have a range of -1 to 5 with step set to 1, then it moves between -1 and 5. If you set the range to -2 to 5, it moves between -2 and -1.
If the range is -1 to 5 with step set to 0.1 it moves between -1 and -0.9.