Region tooltips can show incorrect sizes

1. Open barbar_10.tif.
2. Set the scale manually: draw the line along the scalebar normally, but enter the reference length as "2000 um" (not 2 mm).
3. Segment the photo automatically.
4. Compute measurements: abdomen:Area, abdomen:OrientedBoundingBox(W+L).

In the measurement table, the values are displayed as expected, in um (and at least the OOBB dimensions seem to be correct: 2684.21 um, 1657.89 um).

However, in the region on-hover tooltip, the dimensions are in mm, and zero (also, there's no distinction between OOBB width and length):

Strangely, in the Graphosoma photos with scalebar reference length "200 um", the on-hover tooltips show dimensions in um, correctly. As of now, I don't know if the difference is in the fact that "2000 um" is larger than 1 mm, in the fact that some other photos in the project may have different scale units, or possibly the history of a photo's scale settings.