Disabling minimize control button on Linux (Lubuntu 18.04)

[GoodGuy]

Hello there,
I am using Qt 5.12.3 and i'm try to disable a minimize window control in my application. The application can have 2 window instances. The problem is a diffrent behavior for this same flag settings on Windows and on Linux Lubuntu 18.04.

I'm setting flag in this way :
flags: Qt.Window | Qt.WindowTitleHint | Qt.WindowMaximizeButtonHint | Qt.WindowCloseButtonHint;

For Windows it's working properly, the minimize control is grayout and disabled.
For Linux this settings haven't any impact on this button, it's still working and have got normal color.

I was also try to set flag to Qt.Dialog or Qt.SubWindow to check if there will be any impact but nothing was change ( There should be left only close button)

Is there any reason of this behavior? How it's any other way to disable window controls on linux?

[SGaist]

Hi,

What window manager are you using ?
Are you experiencing the same with another one ?

[GoodGuy]

@SGaist I've got LXDE window manager. To be honest i wasn't test it on another manager.