### Godot version

v4.2.dev.custom_build [c3b0a92c3]

### System information

Debian Linux X11 Xfce

### Issue description

In the following scene tree it is not possible to write anything in `LineEditB`.
![image](https://github.com/godotengine/godot/assets/6299227/ce5f696a-d86a-402f-98f7-6a762f15543e)

I would expect, that it is possible to focus `LineEditB` with a mouse click and write into it.

Regression from #58334

### Steps to reproduce

1. Load and run MRP
2. Mouse Click into the left LineEditB
3. Type Keyboard => No letters appear in the LineEditB

Variant:

1. Load and run MRP
2. Mouse Click into the right LineEditA
3. Mouse Click into the left LineEditB
4. Type Keyboard => Letters appear in LineEditA instead of LineEditB


### Minimal reproduction project

[BugKeyInputRouting.zip](https://github.com/godotengine/godot/files/11994804/BugKeyInputRouting.zip)

ERR_FAIL_NULL(p_control);
	ERR_FAIL_COND(p_control->is_inside_tree());
	ERR_FAIL_COND(p_control->get_parent() != nullptr);
	Control *drag_preview = _gui_get_drag_preview();
	if (drag_preview) {
		memdelete(drag_preview);
	}
	p_control->set_as_top_level(true);
	p_control->set_position(gui.last_mouse_pos);
	p_base->get_root_parent_control()->add_child(p_control); 
	p_control->move_to_front();
	gui.drag_preview_id = p_control->get_instance_id();
}
Control *Viewport::_gui_get_drag_preview() {
	if (gui.drag_preview_id.is_null()) {
		return nullptr;
	} else {
		Control *drag_preview = Object::cast_to<Control>(ObjectDB::get_instance(gui.drag_preview_id));
		if (!drag_preview) {
			ERR_PRINT("Don't free the control set as drag preview.");
			gui.drag_preview_id = ObjectID();
		}
		return drag_preview;
	}
}
void Viewport::_gui_remove_root_control(List<Control *>::Element *RI) {