Maininterface doesn't appear

My figure stands in a room and can play with a IPad. Then a Menu will shown, with a riddle. For this, i make the maininterfaces disappear (for example the inventory). There is a button to go back (to the room where the character is standing), and the button should also make the maininterfaces appear, but it doesn't. Where could be the fault?

menu scenes don't generally allow interfaces to show up ...

for some reason when do allow interfaces on menu scenes they seem to like positioning themselves in the top left corner.

you could; if you preferred add extra interface classes & add an interface with a transparent background png image at same height/width as your default game resolution & set the interface area to the full size of the interface to prevent the user from clicking on the scene behind.

if you plan on using the menu scenes then you may as well add the objects/buttons into the scene itself.

It's not just in menu scenes, this also happens in "Kulissen" (i don't know the right english word).
And they doesn't change the position, they didn't even appear.

I have a solution for this, i can make "show all interfaces" and then "hide inventory, hide secondary interfaces, hide [...]" etc.
This works! So i can make all interfaces appear and single ones disappear. It's just gonna be annoying, when there are more interfaces, i'm in the first room and there are already 14 >.<

there's a show single interface action too.

have you assigned the interfaces to the character?
if you assign them then you need to hide them in the game start actions ...

I use global "call by other action"'s which I tend to create inside of my main character then it's a simple matter of calling the action via "call action" action & then adding the additional required actions afterwards.