Setup custom scaler: Move operation not working with key combination "R + D-Pad" as hint says

Environment

Menu > Options > Display > Setup custom scaler.
Under circumstances: #283
If you happen to see them, you still have a problem:
Hint says: d-pad resize. R+d-pad move.
- D-Pad: → ✅ Indeed resizes.
- Pressing right-shoulder button + D-Pad: → ❌ Does not move but just resize.
  - My right-shoulder button is definitely not broken, works elsewhere in PCSX.
  - Also tried all other modifier keys, and the literal "R" key. → None of them caused a move operation.
I do not know whether just the key binding is broken or whether the move operation itself is broken. But I guess it is rather the key binding, because the D-Pad part of it still triggers. So I guess just the modifier key part is not working.