Quick editing a Zoom meeting using the pencil icon on Moodle can lead to unexpected behaviour.
This includes changes to a meeting's name not carrying over to the Moodle calendar. As well, it has been reported that changes to a meeting name do not always carry over to the Zoom web portal, and will revert after a period of time.
This has been flagged to the developers of the Zoom plugin to investigate.
Avoid renaming if possible.
If you do need to rename something, edit the Zoom meeting, and update the name on the settings page.
If the issue persists, create a new Zoom meeting and delete the old.