Hello. I am having some difficulty in the 2.8 Operator Panel. When I load a new mesh, like a cylinder the operator panel comes up and I can adjust the cylinder's vertices. Once I click on the view port the Operator Panel disappears. If I want to change the cylinder's vertices again, it seems logical that could be done by opening the Operator Panel and adjusting the vertices but, I cannot seem to find a way to open the panel again. I can find all of the other parameters in other panels but not vertices. Please help.
The operator panel is finicky that way. It only shows the settings of the immediate operator performed. Since selection (i.e. clicking in the viewport) is an operator, the previous operator settings disappear.
You can orbit, pan, and zoom in the viewport but simple things like selecting an object, moving, rotating, etc will replace the operator panel and you can't undo back to regain the former settings. I agree that it can be annoying but it's the way it's designed to be... 😕