hello What I found seams to me pretty funny (actually sadly funny)

Can someone please explain this to me?

Two arc of cirle; the fist one defined the second one not. I apply to the second one relation -> equal to previous arc. Solidworks apply the relation but...... doesn't change the dimension at all!!!   no errors .. no red or yellow allerts... I try to riconstruct with the "traffic light command".. it remains like you see in this picture...

I bet this time it's not my fault! Did I finally found a bug? 

M.