Hi everyone.
I’m gonna put this here just in case someone else need it.
When you press Alt-Tab, by default, you only see the window outline (an empty, transparent box) but sometimes, like in my case, is handy to see the actual content of the windows.
In order to change this behavior, edit your ~/.config/openbox/rc.xml and change the raise value from “no“ to “yes”:
<keybind key="A-Tab">
<action name="NextWindow">
<dialog>icons</dialog>
<raise>yes</raise>
<allDesktops>no</allDesktops>
</action>
Regards.