### 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_READ_THREAD_GUARD_V(false);
	return use_xr;
}
void Viewport::set_scaling_3d_mode(Scaling3DMode p_scaling_3d_mode) {
	ERR_MAIN_THREAD_GUARD;
	if (scaling_3d_mode == p_scaling_3d_mode) {
		return;
	}
	scaling_3d_mode = p_scaling_3d_mode;
	RS::get_singleton()->viewport_set_scaling_3d_mode(viewport, (RS::ViewportScaling3DMode)(int)p_scaling_3d_mode);
}
Viewport::Scaling3DMode Viewport::get_scaling_3d_mode() const {
	ERR_READ_THREAD_GUARD_V(SCALING_3D_MODE_BILINEAR);
	return scaling_3d_mode;
}
void Viewport::set_scaling_3d_scale(float p_scaling_3d_scale) {