I have my abilities set to “Q”,“W”,“E”, and “R” and my “Shift” is to stand in place while I cast. I can cast everything, except the ability which is mapped to “R” while holding “Shift”.
For some reason “Shift” + “R” is not recognized by the game, the way “Shift” + “Q” is for example.
First I thought this was a Windows Shortcut of some sort which interferes with the game and hence nothing happens, but this combination of keys are used in other applications, so I think it is a bug.