Logs are logs though as that's the data you have to look at.
You ran out of quota and that's the only message you got so you have to wait it out unfortunately.
You have intro analysis? You have extended analysis? Is someone syncing a show to download? Is it shared? Is a team drive? Is it a GSuite account?
There are a number of reasons you can hit quota depending on what settings you have in Plex or many other applications as there's nothing that rclone can do to prevent that unfortunately.
You can wait it out.
You can contact support and ask what the reason is and perhaps they can shed some light as well.