Comment 16 for bug 1850103

SOLVED: I found the fix for the gnome-tweak tool. In my case, it turns out the rapid flickering occurs when Animations is disabled in the GENERAL page of GNOME-tweak. Re-enabling Animations stopped the window flicker. There is another minor artifact -- the Close-Minimize-Maximize-Search icons disappear from the application bar when using "<" to return to the main menu. But they do reappear when further clicking on page links in the left menu. The page link menu and the page menus display separately now in independent windows -- and this was the initial behavior I remember before disabling Animations.