[Mac OS] Setting maximumSize to smallish value makes Qt think the window is maximized

I make a top-level QMainWindow. I set QWidget::setMinimumSize(QSize(144,144)). This triggers a changeEvent with a QWindowStateChangeEvent reporting that the window was maximized. In fact, Qt has marked the window as maximized.

I have attached a zipped toy application that shows the problem. Running the application puts up a QMainWindow with a button "Apply Size Limit". The signal handler for QPushButton::clicked calls setMaximumSize(QSize(144,144));

An override for QWidget::changeEvent() is triggered by that call. My implementation gathers information on the window state and uses qDebug() to print out some of that info. Using Qt 5.12.9 or 5.15.0 I get this printout:

2020-08-28 09:45:59.215641-0700 InvestigateSizeLimit[2282:92243] Change event: wasMaximized: false , wasFullScreen: false2020-08-28 09:45:59.215641-0700 InvestigateSizeLimit[2282:92243] Change event: wasMaximized: false , wasFullScreen: false2020-08-28 09:45:59.215666-0700 InvestigateSizeLimit[2282:92243] now maximized: true , now full screen: false

I ran this on Mac OS Mojave, 10.14.6. I could test on El Camino if necessary. Big Sur might be possible if my boss is willing

I tried to attach a zipped Qt Creator project, but I get a message, "Jira could not attach the file as there was a missing token. Please try attaching the file again." Do you not accept zipped files?