Rhino 8 Feature: Improved UV Mapping

Hi again @BrianJ
Is it correct, the I can’t seem to get two UV islands to constrain to a single set of curves? In this case it’s two identical ends of a shopping bag, that will share the same UV space, but I can’t get the second one to constrain to the curves. The little green lines showing which vertex goes where doesn’t pop up for the second island. Am I doing something wrong or…?
TIA, Jakob