Snapping to centre - Osnap looks like it's turned on but snap isn't working?

Hi, I’m running the free trial of Rhino, so I’m assuming that it’s the most up to date version. I’m just doing a 2D drawing. I thought I turned on Osnap and Centre Snap (I want to rotate a group of curves from the centre of a circle that’s part of that group of curves), but it doesn’t seem to be snapping to the centre of the circle when I hover over the circle with my cursor. I’ve tried ungrouping the objects, hovering over while the circle is selected and when it’s deselected, checking and unchecking the centre box at the bottom as well as clicking the icon, and turning the program on and off, but nothing has turned Osnap back on.

This is especially weird because it was working before. Other snaps were also working before, Near, End, etc, but they seem to turn on and off randomly. Sometimes they’ll work and sometimes they won’t, even though their boxes are checked at the bottom. I think I must be inadvertently toggling them on and off somehow but I have no idea how. How can I fix this?

To use the OSnap the cursor needs to be near the circle, not anywhere inside the circle.

If the circle is rebuilt as a regular NURBS curve then the Cen OSnap will not work. It only works on certain types of objects.