### 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.)
Vector<Viewport *> result;
	List<Viewport *> nodes;
	for (int i = active_viewports.size() - 1; i >= 0; --i) {
		Viewport *viewport = active_viewports[i];
		if (viewport->parent.is_valid()) {
			continue;
		}
		nodes.push_back(viewport);
		result.insert(0, viewport);
	}
	while (!nodes.is_empty()) {
		const Viewport *node = nodes[0];
		nodes.pop_front();
		for (int i = active_viewports.size() - 1; i >= 0; --i) {
			Viewport *child = active_viewports[i];
			if (child->parent != node->self) {
				continue;
			}
			if (!nodes.find(child)) {
				nodes.push_back(child);
				result.insert(0, child);
			}
		}
	}
	return result;
}
void RendererViewport::_configure_3d_render_buffers(Viewport *p_viewport) {