PySide6 QFontDialog - bug or just me?

[PatM]

I have a qfontdialog that works ALMOST perfectly BUT I am having one issue.

When I first start the program I use

self.font = QFont()
self.font.setFamily("Sans")
self.font.setPointSize(15)

(and later)

        print("Font is", self.font)
        fdlg = QFontDialog()
        fdlg.setCurrentFont(self.font)
        fdlg.exec()
        font = fdlg.currentFont()
        if font:
            print("Change to", font)
            self.font = font
            Settings.fontFamily = self.font.family()
            Settings.fontSize = self.font.pointSize()
            self.getCaptionedImage()
[

The problem is that the dialog doesn't show any selected font (No line highlighted), But if I change to "Serif" then one is highlighted. If I run this and choose a diffferent font then when I reopen that font is highlighted. EXCEPT not if I choose "Sans Regular", that results in no selected font after I open a third time.

Seems like a bug where the system ignores Sans Regular but is it really?