ArcGIS Pro 2.2.4 isn’t exporting to geotif or pdf the entire map view, just the central area as a square. Layouts are fine. I typically use ArcMap to do this but I think I’ve used Pro on imported ArcMap projects in the past and never had this problem. I've tried it on a second computer with the same odd results.
ESRI tech support just indicated to me this is a known defect to be remedied in 2.3.
Still happening in 2.3.2... guess I'm going back to ArcMap to make the slides I need at 16:9 ratio