QSystemTrayIcon does not show context menu on primary screen on macOS

Environment

• macOS Catalina (10.15.6) on a MacBook with retina screen
• a second screen (non-HiDPI) attached "above" the primary laptop screen
• using conan-built Qt 5.15.0

Screen arrangement

Steps to reproduce

• build and run the systray example on macOS
• application renders the tray icon on both screens
• clicking the tray icon on the low-res secondary screen opens the context menu
• clicking the tray on the laptop's high-res primary screen does not open the context menu

Expected behaviour

• context menu should open on both screens

Screen Cast

Please note the screen casts attached below. The actual tray icon is not visible for some reason: I guess, because we do not compile PNG support in our build of Qt.