Plex shows the remote access status as „green“ while testing the connection. If it turns red after a few seconds, it just means it doesn’t work to begin with.
Have you already checked if your forwarded port is visible outside your home network? You can do this using a service like canyouseeme.org. If you do that, you can also verify if the public IP address reported by canyouseeme.org is the same one seen in the Plex Media Server‘s Remote Access settings and the WAN IP listed in your router.
