[e-users] Mouse-clicks not arriving as GUI event with windows using a border/title

Hi everyone,

since a couple of days I realized there is a nasty bug somewhere that 
prevents left-clicking the mouse on a button in a GUI (QT, GTK3 and E 
itself) is no longer working when the window has a border (dialog-border 
in most cases). As I use a borderless desktop not all windows are 
affected by this bug but ie. Eclipse IDE has many dialogs with a border 
which I have to navigate by keyboard (TAB to navigate and later Space to 
select). I use X11 / XLibre and run E from git on Gentoo. I remember to 
have had such a bug years ago but I am totally unaware how fix it now. 
Is there - as a workaround - a way to force all windows borderless, even 
the E core ones?

I tested this using "qt5ct" which displays an info in the top part as 
one of my env variable is messed up. The popup uses a dialog border by 
default. When I use the window's context menu and change the border from 
dialog to borderless I can afterwards use the mouse to click on the OK 
button.

I cane help to further debug this as I compile E from source. Please 
just give advice on what to do/check.

Thanks in advance for any feedback!

Best regards,
Marc