### 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.)
if (p_viewport->render_buffers.is_valid()) {
		if (p_viewport->size.width == 0 || p_viewport->size.height == 0) {
			p_viewport->render_buffers.unref();
		} else {
			float scaling_3d_scale = p_viewport->scaling_3d_scale;
			RS::ViewportScaling3DMode scaling_3d_mode = p_viewport->scaling_3d_mode;
			if ((scaling_3d_mode == RS::VIEWPORT_SCALING_3D_MODE_FSR) && (scaling_3d_scale > 1.0)) {
				
				
				scaling_3d_mode = RS::VIEWPORT_SCALING_3D_MODE_BILINEAR;
			}
			if ((scaling_3d_mode == RS::VIEWPORT_SCALING_3D_MODE_FSR) && !p_viewport->fsr_enabled) {
				
				
				WARN_PRINT_ONCE("FSR 1.0 3D resolution scaling is not available. Falling back to bilinear 3D resolution scaling.");
				scaling_3d_mode = RS::VIEWPORT_SCALING_3D_MODE_BILINEAR;
			}
			if (scaling_3d_scale == 1.0) {
				scaling_3d_mode = RS::VIEWPORT_SCALING_3D_MODE_OFF;
			}
			int width;
			int height;
			int render_width;
			int render_height;
			switch (scaling_3d_mode) {
				case RS::VIEWPORT_SCALING_3D_MODE_BILINEAR: