This happens consistently when I try to manipulate tables inside Affinity Publisher 1.7.1 on MacOS X Mojave 10.14.5:
Randomly, while editing documents, when I try to edit a table by double clicking using the Move Tool, the controls that show the table's column and row numbering and the controls that allow you to add rows/columns by dragging them, disappear (as in, are not shown anymore around the table). The only way to get them back is by closing and re-opening Affinity Publisher. This makes working with tables a real pain.
The first few times after re-opening the application everything seems to work as expected, but after a while this situation repeats itself. Every. Single. Session.
Am I missing something or is this indeed a seriously annoying bug?