Movement trails only showing for selected unit -- how can I make them stay?

I have been trying to tweak the Blue and Gray module for Cemetery Hill (Module:Blue & Gray: Four American Civil War Battles - Vassal) to have movement trails that persist.

I have set the movement trails attribute as follows:

(that’s for usaUnit, but the same is for csaUnit)

I see movement trails now, but only for the currently selected unit. When I select another unit the first unit’s movement trail disappears. When I select it again, it’s trail reappears.

I would prefer the movement trails persist until dismissed. How would I do this? I thought that setting the “Unselected unit trail transparency” to 100 would make that happen, but apparently it does not.