Tab key advances through Properties (and event editor) fields, but shift-tab does not always go backwards
When editing data in the property panel, pressing the tab key correctly moves forward from field to field, as shown in this GIF animation:
Unfortunately, pressing Shift-Tab does not reverse that process, as shown in this GIF animation, in which I first quickly tab through the Left, Top, [Left/Top lock], Width, Height, [Width lock], [Height lock], [Width/Height chain] fields to the Angle field, then repeatedly press Shift-Tab, with the result that the Angle field repeatedly highlights and un-highlights:
What my screen capture utility, Recordit, did not capture is that at the moment the Angle fields toggles from white to black, the "Absolute Position" label below it momentarily has a light grey border, as though it was being selected, then instantly de-selected.
I hope this helps you troubleshoot this admittedly small, but workflow-delaying bug.