Robert1893: In fact, earlier in this thread, Scott posted a comparison of 2019 to today. And below is a screenshot from a practice round I played in December 2020.
Yes I saw Scott's post and wondered if something was done inbetween changing from front view to rear view. If it has always been there in rear view it must have been so insignificant that I just didn't notice it (and bear in mind I almost always putt in rear view), unlike the new line which is so thick it obscures other things that are more important, i.e. the dots.
I said there that I wondered if Scott had done something inbetween changing from front view to rear view, and the reason I said that is because on occasion I think I have previously seen a line, when accidentally clicking to the right of the camera and getting one of the other views, then when I've got back to the main view I think the line has been there. But that is the only time I recall seeing it.
Just one last question, was that line always there in rear view, or did it just show up when you clicked on the marker to move it, and then disappear again when you let go of the mouse? That might explain why I never thought I'd seen it before.