Thanks Jerome. And doesn't tab do just the same as ctrl-tab ? That's why I used to use ctrl-tab for grid switching in the first place. But maybe I should check the default "installation".

 

I manually reassigned the shortcut in

 

Customize->Keyboard->Windows -> Next Tab  / Previous Tab

 

And it now works.

 

Maybe was it never the default behavior...? I thought it was, but I just saw it's ctrl + page down / page up...

 

Sorry about that ! :)