Reverse shift clunking?

This sounds more like an engine/transmission mount. Can you please shoot a quick video with your phone so I can hear the noise? That way I can tell for sure what's going on. You can upload it here with your response. Do you have any trouble codes? I would lift the hood and watch from the side of the car while you have a helper start the car and put it in reverse and then into drive and watch for excessive movement which is telling you the mounts need to be replaced.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please go over this guide and get back to us.