Indeed very possible Qt 6 has a whole new set of issues.
Concerning the slider, I found this issue for Monterey yet I didn’t test yet if such happens for me.
https://bugreports.qt.io/plugins/ser...ue/QTBUG-98093
Of the look of the slider, I think you’re using TicksBothSides? I haven’t really looked yet I think on macOS, below might be the preferred choice. At least such seems to be the case from some screen shot from Apple’s Human Interface Guidelines.
From Apple’s API, below and above seem to be the only valid options and I am not sure what Qt does when set to both.
https://developer.apple.com/document...ckmarkposition