When I press the TAB key in the Positron editor panel, this changes the focus and goes thru the cycle of panels and buttons. How can I change that behavior to enter an actual tab into the editor? I've gone thru the settings, and can't find anything relevant.
By any chance, is there a "Tab Moves Focus" label on status bar?
You can disable it with a click. Or search for it from command palette ("tab focus" should do). You most likely toggled it with a shortcut key, in Windows the default seems to be Ctrl+M.