Unusual issue after upgrading to ver 4

[TheMouseAUS]

My Distro has recently upgraded form version 3.6 to 4.0. I was expecting a few bumps but one specific one has made me roll back to 3.6. On the main form I have a login button that shows another form with a TComboBox for the user name, a TEdit box with echo mode set to emPassword and an TButton for enter (this closes the popup form). This form style is set to fsSystemStayOnTop no border icons. When I compile under Lazarus v4 and run the application the first time the Login form shows everything works as expected, but after the popup has been closed and shown again it stops accepting mouse input. Keyboard still works and I can tab between the components. Close the app and open again it will work again properly for one time only. I tried compiling in both QT5 and QT6 same result. I rolled back to 3.6 and behavior was correct again. Its very unusual.

Lazarus 4.0
FPC 3.2.2
Plasma 6.3.5
x86_64-linux-qt6

[zeljko]

Looks like qt5/qt6 bug in lazarus 4.0. Please fill issue about it, also attach simple project which reproduces bug, so I can fix it in reasonable time and merge to fixes_4, so you'll get it fixed in Lazarus 4.2.

[TheMouseAUS]

I created a new project with two forms. On the second I had fsSystemStayOnTop flagged and called it from the first form. Behaviour was as expected.

Went back to my project and sent all my different popup forms to fsNormal instead of fsSystemStayOnTop and found the call Form.showModal keeps the form on top anyway and the form does not stop accepting input any longer. So i think there was an issue somewhere with the Forms (except the main one)  being set to stay-on-top (even though only one was ever displayed at one time).