Asymmetric range causes screen garbage [SOLVED]

Working on a Micron editor and ran into something setting up a Filter Keytrack fader.

The range is -100 to +200 for keytracking. Alesis is using 14 bit, 2’s complement signed NRPNs.
If I set up a fader for -100 to 200, 2’s complement and sweep the fader range, the positive ranges are fine. Once I start going negative and I get to about -39, the numbers start writing past the left edge of the bar until I get to about -63, then they start writing back inside the bar as always.

The values are being sent correctly, but the screen is messed up until I send down a new copy or refresh the screen by changing pages.

Testing with the interim version provided by Martin has fixed this issue.