### Godot version

v4.0.beta12.official [3c9bf4bc2]

### System information

Windows 10, AMD Radeon RX 480 4 GB RAM, 16 gb ram, Intel CPU 4 cores.

### Issue description


When switching to mobile render from forward + The alpha texture on the tree mesh starts to flicker.
Made a video: https://www.youtube.com/watch?v=WdGVi1hdRHo



### Steps to reproduce

Switching to mobile render from forward +

### Minimal reproduction project

Uploaded the project in google link: https://drive.google.com/file/d/1efEV914CWkyWoGzkv3RBMnw9t-4BVTeQ/view?usp=sharing
(only deleted the .godot - i guess its not needed.)
RID *vp = timestamp_vp_map.getptr(p_timestamp);
	if (!vp) {
		return;
	}
	Viewport *viewport = viewport_owner.get_or_null(*vp);
	if (!viewport) {
		return;
	}
	if (p_timestamp.begins_with("vp_begin")) {
		viewport->time_cpu_begin = p_cpu_time;
		viewport->time_gpu_begin = p_gpu_time;
	}
	if (p_timestamp.begins_with("vp_end")) {
		viewport->time_cpu_end = p_cpu_time;
		viewport->time_gpu_end = p_gpu_time;
	}
}
void RendererViewport::set_default_clear_color(const Color &p_color) {