When using a SubViewport the behaviour-handles are shown

[SaturnHafen]

When using a SubViewport the handles are rendered in the exported game.

[tom95]

The bug is actually not related to viewports -- you will notice that in your scene, there are a lot of nodes that start with an underscore. These are so-called internal children that are supposed to be invisible and are not serialized to the scene.

I think what happened might be that all the internal children got copied as non-internal children when you moved nodes to the new scene? Do you remember how you went about creating the second scene?

[SaturnHafen]

Do you remember how you went about creating the second scene?

We used the right click -> Save branch as scene workflow to create the new scene.