Problem with buildMenuWithBuilder and scenes

Bonjour, I have an (old) app. written in Objective-C which works fine under iPadOS 26 with custom menus and contextual menus but without scenedelegate. To be able to have multi-windows, I added scenedelegate but "buildMenuWithBuilder" is no more called. I asked AI Claude and tried many solutions but none worked. Has anyone else had and solved this problem?

Thanks.

Problem with buildMenuWithBuilder and scenes
 
 
Q