Piano Roll editor does up clear vertical Red cursor line when clicking a different note

First let me note that this bug does not happen in current 3.0-dev master ce09d98, although it is present in 2.1 and 2.2 5bdaff8, so I'm marking as "fixed" since 3.0 will have the fix...unless someone wants to fix this for a 2.2 release. Unless I simply haven't figured out how to reproduce it in 3.0

Repo steps: view piano roll editor for a staff with more than one note. Click on a note, observe the red cursor line (which is fine for one note). But then click on another note and see that there is a new cursor line drawn correctly, but the old one incorrectly remains.

Note that resizing the window will cause the old cursors to be correctly removed. Also note that sometimes if the piano roll window is small, then this glitch isn't present, but is more likely to be present when the piano roll window is big, and curiously the problem is more likely to happen with wide a wide window, but not a tall window...