### 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.)
Viewport *viewport = viewport_owner.get_or_null(p_viewport);
	ERR_FAIL_COND(!viewport);
	RSG::texture_storage->render_target_set_vrs_texture(viewport->render_target, p_texture);
	_configure_3d_render_buffers(viewport);
}
bool RendererViewport::free(RID p_rid) {
	if (viewport_owner.owns(p_rid)) {
		Viewport *viewport = viewport_owner.get_or_null(p_rid);
		RSG::texture_storage->render_target_free(viewport->render_target);
		RSG::light_storage->shadow_atlas_free(viewport->shadow_atlas);
		if (viewport->render_buffers.is_valid()) {
			viewport->render_buffers.unref();
		}
		while (viewport->canvas_map.begin()) {
			viewport_remove_canvas(p_rid, viewport->canvas_map.begin()->key);
		}
		viewport_set_scenario(p_rid, RID());
		active_viewports.erase(viewport);
		sorted_active_viewports_dirty = true;
		if (viewport->use_occlusion_culling) {
			RendererSceneOcclusionCull::get_singleton()->remove_buffer(p_rid);
		}
		viewport_owner.free(p_rid);
		return true;
	}
	return false;
}
void RendererViewport::handle_timestamp(String p_timestamp, uint64_t p_cpu_time, uint64_t p_gpu_time) {