QMenu take Main Window focus

Hi!

I have some weird behaviours when I try to open Dialog Windows.
After some test, I think that the problem come from my menu bar (I can reproduce the same behaviour without opening windows).

When I click on an empty QMenu (without QAction inside), nothing happen and nothing change (which is normal).
But when I click on a QMenu with QAction inside (a drop-down menu), that's where things are weird. The QAction don't do anything, they are not link to a slot or anything else. When I click on such a QMenu, without clicking or even hovering the QAction, I "lose" the focus on my Main Window.
By that I mean that I can't resize my Main Window, nor move it with my mouse.

Even weirder ? All the buttons inside the Main Window and their associated actions are still working. I use my Central Widget to catch mouse events (to interact with some data), and this still works too (before and after I clicked on the QMenu). The QAction in the Menu Bar are still working.

Its like the Main Window frame lose the focus....

Do you know why this happen and/or how to get the focus back to Main Window ?

I solved the probelm. My centralWidget grabbed to keyboard for some of its functionnalities. I just commented the line "grabKeyboard()" and everything function as intended..