The default in Creator is (or was) to have the "Debugger Perspectives" (stack) on the left and the Breakpoints on the right. This makes sense as the call stack is interacted with more often, and breakpoints can be set in the editor. I've found that, since 4.8, Creator will sometimes switch the positions, and clicking "Reset to Default Layout" sometimes works (switches Breakpoints to be on the right) and sometimes does not.