I can reproduce on this MacOS with slight variations. As you describe I create a closed curve and then enable some of the measurements (length, curve, curvature, curvature max) and then drew another curve
on 5.10.
Second curve displayed the length only.
on 5.11 from June 2nd
Second curve displayed all three measurements.
I agree this a bit confusing, since I always thought to be property of individual markup object as opposed to default on and off (and if it is a global on/off, then one can argue it is in the wrong place in the UI).