2018r4 - Control Sets

I created 5 buttons on a window (button1-button5)
went to combine them into a controlset.
normally if I changed the name of button2 to button1 it asked if that was what I wanted to do, and then made btn[1] and btn[2] etc.

Now it doesn’t… it changed the name of btn2 to btn1 giving me duplicate named controls
then the IDE gets more confused.
If I select what had been BTN1 and attempt to change its name to something else, it changes the name of what had been BTN2 instead

giving no way to create a control set, nor any way of recovering short of reverting the code

seems r2018r3 does the same thing, and so it seems does r2016r4

Turns out this is occuring ONLY with a custom control (subclass canvas), and does work properly with standard controls?

Any ideas?

SOLUTION : in Inspector Behaviour - DO NOT HIDE “SUPER”

I think this is a bug, but this is the workaround… Most won’t hide Super to begin with, but in this case I did and that seems to be what caused the issue