ViewportTexture throwing errors after running the scene.

[Kerotasma]

Godot version

v4.0 rc6

System information

Windows 10

Issue description

When using a ViewportTexture from a SubViewport on a TextureRect, it throws errors after running the scene once and then switching scenes in the editor.

Steps to reproduce

Run the canvas-scene once.
Switch to another scene in the editor.
Switch back to the canvas-scene

Minimal reproduction project

ViewportTextureError.zip