QPushButton has square edges on some macOS 26 Macs

AndyBrice

A couple of my customers are reporting that QPushButtons in QDialogs look like this on macOS 26:

(low contrast, square buttons)

For myself and the majority of my customers on macOS 26 they look like this, as expected:

I haven't been able to work out why this is.

I have tried changing various Display and Accessibility settings on my Mac. But I can't reproduce the problem.

I tried setting UIDesignRequiresCompatibility key in Info.plist to true, but that made no difference ( https://www.qt.io/blog/qt-on-macos-26-tahoe ).

I am building with Qt 5.15.18 (I know) using XCode 14.2.

Any ideas?

AndyBrice

I found this:

But it didn't give me any clue as to why I get square buttons on only some Macs.