Corner rounder freaking out

Think I found a possible bug. Working on some halloween designs and doing a small corner rounding (2mm on a 60mm tall item) I click on either of the bottom corners of the item shown on the bottom and the end result is the item shown on the top. Now you can see I did the same 2mm rounding on the sides and top shoulders with no issues but when I try on the bottom corners it freaks out and makes the hole thing pointed at the bottom and over 100mm tall then.

I really wanted to just break the sharp corners a bit but right now I am at a loss since the corner rounder is freaking out.

Any ideas?