Selecting a highlighted variable affects background of all occurrences of the variable

When the cursor is on a variable name, all visible mentions of that variable in the code become highlighted with a light-yellow border and no other color changes. However, when that variable becomes selected, this affects background of all mentions of the variable. See the attached video for an illustration.

I can see the "Occurrences" entry in the "Font & Color" settings, that entry matches the light-yellow color used for the border. But I cannot see any setting that would match the background color of the occurrences when the variable is selected. In fact, I would prefer that change in the background color to be disabled (i.e. so that selecting the variable does not affect the presentation of the other occurrences of the variable).

This is a regression in QtCreator 13.0.0 beta1.