open the document. zoom in a little. use shape editor, drag a single node a little. repeat with other nodes and notice the glitch. can you confirm?
https://www.dropbox.com/s/4bwnsgtq4e1ifyo/bspline_node%20bug.cdr?dl=0
I'm aware of a number of situations where "on-screen" content is not being properly refreshed in 2019.
Try zooming in or out using Zoom One-Shot, or the scroll wheel, or shortcut key, or anything else that shouldn't take the Curve out of editing mode. All kinds of craziness!
It messes with one of my macros that uses on-screen curves, too.