Using SW'18 SP3, I have modeled a very simple sheet metal "box" by extruding a 10" square 2.5" tall, and Convert to Sheet Metal. The material is 0.125" thick with matching bend radius. When I move down and attempt to change the Auto Relief Type, SolidWorks acts strange. The selected relief type is not reflected in the graphics window. Selecting "Rectangular" acts as a "Tear" and even makes the Relief Ratio input box disappear, Where as selecting "Tear" acts as a "Square" and even offers me the Relief Ration option.
I've tried refreshing, reopening, rebooting... The problem doesn't happen every time I convert a solid to sheet metal, but it is persistent to that part, once it has happened. Nothing seems to correct the error, once it has happened.
I searched the forums and found this post from Nov 2014 - https://forum.solidworks.com/message/464641?q=auto%20relief
I have to wonder if this bug has been around since then?