ComboBox dropdown displayed on incorrect screen in multiscreen environment

Setup:

My laptop can connect 2 external monitors, so I have a maximum of 3 screens. Whenever I expand windows desktop across the 3 screens, if I open a Qt dropdown when the application runs on the 3rd screen, it's always displayed at the edge of the 2nd screen (like if the desktop bounding box is clipped to the primary and secondary screens only). No fancing display scaling, all at 100%.

Additional tests:

• No issue with Qt 5.15.2
• Same result if the primary screen is declared on internal display, or on either of the external monitors
• Same result if the internal display is disabled or not (even when disabled it still shows in windows monitors arrangment, so I guess it's taken into account for the full desktop coordinates)
• Restoring main application geometry exhibit the same bug: If geometry is saved on the 3rd monitor, it's always restored on the 2nd one