### 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(MSAA_DISABLED);
	return msaa_2d;
}
void Viewport::set_msaa_3d(MSAA p_msaa) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_msaa, MSAA_MAX);
	if (msaa_3d == p_msaa) {
		return;
	}
	msaa_3d = p_msaa;
	RS::get_singleton()->viewport_set_msaa_3d(viewport, RS::ViewportMSAA(p_msaa));
}
Viewport::MSAA Viewport::get_msaa_3d() const {
	ERR_READ_THREAD_GUARD_V(MSAA_DISABLED);
	return msaa_3d;
}
void Viewport::set_screen_space_aa(ScreenSpaceAA p_screen_space_aa) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_screen_space_aa, SCREEN_SPACE_AA_MAX);
	if (screen_space_aa == p_screen_space_aa) {
		return;
	}
	screen_space_aa = p_screen_space_aa;
	RS::get_singleton()->viewport_set_screen_space_aa(viewport, RS::ViewportScreenSpaceAA(p_screen_space_aa));
}
Viewport::ScreenSpaceAA Viewport::get_screen_space_aa() const {
	ERR_READ_THREAD_GUARD_V(SCREEN_SPACE_AA_DISABLED);
	return screen_space_aa;
}
void Viewport::set_use_taa(bool p_use_taa) {