### Godot version

4.2 eca6f0e

### System information

Windows 10 x64

### Issue description


https://github.com/godotengine/godot/assets/2223172/a2796263-4e2e-4b14-a080-b3ad034cc141



### Steps to reproduce

1. Add SubViewport
2. Add Sprite2D
3. Set spirte's texture to ViewportTexture
4. Create new scene
5. Instance the new scene inside the scene with viewport
6. Make sure both scenes are opened
7. Go to instance scene and save it
8. Go to viewport scene

You will see error spam. Reloading the scene fixes it.

### Minimal reproduction project

[vip.zip](https://github.com/godotengine/godot/files/12292386/vip.zip)

if (ABS(dist_y) > limit) {
		return SUB_WINDOW_RESIZE_DISABLED;
	}
	if (dist_x < 0 && dist_y < 0) {
		return SUB_WINDOW_RESIZE_TOP_LEFT;
	}
	if (dist_x == 0 && dist_y < 0) {
		return SUB_WINDOW_RESIZE_TOP;
	}
	if (dist_x > 0 && dist_y < 0) {
		return SUB_WINDOW_RESIZE_TOP_RIGHT;
	}
	if (dist_x < 0 && dist_y == 0) {
		return SUB_WINDOW_RESIZE_LEFT;
	}
	if (dist_x > 0 && dist_y == 0) {
		return SUB_WINDOW_RESIZE_RIGHT;
	}
	if (dist_x < 0 && dist_y > 0) {
		return SUB_WINDOW_RESIZE_BOTTOM_LEFT;
	}
	if (dist_x == 0 && dist_y > 0) {
		return SUB_WINDOW_RESIZE_BOTTOM;
	}
	if (dist_x > 0 && dist_y > 0) {
		return SUB_WINDOW_RESIZE_BOTTOM_RIGHT;
	}
	return SUB_WINDOW_RESIZE_DISABLED;
}
bool Viewport::_sub_windows_forward_input(const Ref<InputEvent> &p_event) {