I wrote a PySide application that should run on python2.7, on window,Linux and Docker container. The application contains Qtooltip and specific eventFilter that catches HoverEnter\HoverLeave.
The application works well on windows 10 and ubuntu 14.04 desktop but when trying to run it inside Ubuntu 14.04 container both features didn't work well:

The tooltip - It would seem that the text is covered by other tooltip text or totally black.
The eventFilter - The application can't get the hover event (didn't appear).

The main difference that I saw was that when running on Ubuntu desktop, some GTk libraries are loaded to the python process (according to the maps files).
I tried reproduce the problem by installing everything on Ubuntu server (without Gtk), and got the same effect as inside the container.
Even after installing Gtk on the server, still no change.
I think that I might have missed some dependencies, but can't find any documentation on the issue. 
Thanks in advance,
Ok, after several days of trying figure that this is what was needed:
For the tooltip problem:

Adding WA_AlwaysShowToolTips 
Change the stylesheet show that the transparent feature will work only for the QPushButton background and not the entire widget.

For the event problem:

Add the attribute: WA_Hover

Everything worked as should be after that
Pyside fail to show tooltip and specific events in Linux