In ArcMap we could round the corners on objects in the layout view. I see that this is (sort of) possible to do in Pro, but is it possible to do with the Map Frame?
In addition, the rounding on the corners of my "border" object seems to be a bit buggy. The top left, right and bottom right corners all round correctly, but the bottom left corner stays squared.
This map below was imported from an ArcMap project. I also tried making a new project and ran into the same issue.