I'm not even looking at the first paragraph and I'm not concerned about the line it was posted on.

What I am saying is I do the following steps (from your message above):

1. Turn on Highlight Active Line in View menu if it is not enabled.
2. Double-click on a word in the editor to select it.
3. Go to View menu and uncheck Highlight Active Line while you still have selection in the editor.
4. Press Left/Right arrow key to deselect the word in the editor.
5. Open View menu and look at Highlight Active Line. It will be checked at this point but there is no active line highlight in the editor.

And I can't repro the issue.

First, we need to address the fact that you can repro problem and I can't.