Doesn't show the slides I choose in the sizes I choose; no support

This plugin evidently has a mind of its own. It chooses the slides it wants to show regardless of the slides I have selected. When I finally manage to coax it to show the slides I’ve chosen, it chooses the sizes in which it wants to show them. ZERO option for changing the sizes in the general settings. And all this is a DIY proposition; no response to my requests for help in the support forum.