When dragging a PDF or Word document into the page thumbnails to add that document to the existing PDF document, the thumbnails occasionally fail to refresh, and show the incorrect page thumbnails.

E.g. If I drag a 3 page document file into page 50 of a 100 page PDF, the thumbnails will show the previous pages 50-52 until you close the thumbnail view and re-open it or scroll the thumbnail view past those pages forcing a refresh.

I am using Adobe Acrobat Pro version 2017.011.30120