right aligned text in spinbox sometimes truncated

QSpinBox does not correctly adjust right-aligned text in some instances, leading to text that is truncated due to running off the right side of the widget.

To reproduce:

• Open attached .ui in designer
• Preview form
• Select slider
• Press end

Expected results:

• Spin box shows '5000 / 5000', with no space before the text (as it fills the widget completely)

Actual results:

• Spin box shows ' 5000 / 5(' with text truncated due to misalignment (the '(' indicates a truncated '0', not an actual '(' character)

Reproducible:

• Always, with multiple styles including built-in styles, using above steps. Similar misbehavior is seen sometimes under normal usage.

Additional Notes:
Selecting the text in the spin box temporarily fixes the alignment. Also, it seems to be related to the difference in old and new values, as dragging the slider from 0 to the end does not show the problem. I've also seen the same problem without a suffix set on the spin box.