I have a document, shown using horizontal split screen.
When I press RETURN in the 1st frame, nothing happens in that frame. But in the 2nd frame the linefeed is shown.
Other"normal" input keys (letters, digits etc.) updates both frames correctly. But linefeed and cursor movement seems to screw things up.
See screen capture. https://youtu.be/djqoLghmc88
Also if I copy something from 2nd frame and select a text in 1st frame and then paste in the clipboard content. then the content in 1st frame is trashed until i move the cursor to a new line.