It is shown correctly. I tried both english and german locale.
Re: QToolTip { padding-right: 10px; }
here this snippet is applied when I add it at the bottom of style-classic.qss
unlikely, but maybe you need to comment out QToolTip in another place where the general padding and border is set.
Can not reproduce. Tooltip displayed as intended.
macOS 10.14
2.4.0-alpha-pre (build main r7762)