QDoubleSpinBox with suffix >1 character, backspace key handled wrong

A QDoubleSpinBox with a suffix whose length is greater than one character and the a cursor is at the end, pressing the backspace is handled wrong as it does nothing and the cursor does not move (very frustrating). 

In contrast, when a suffix is one character and the cursor is at the end, pressing the backspace moves to the end of double value, skipping the suffix text, ready to edit the double value as expected.

Related: https://stackoverflow.com/questions/40756382/editing-behavior-of-backspace-key-of-qdoublespinbox

Would appreciate a fix for the native QDoubleSpinBox so it easily scales across and entire application rather than a subclass fix.