Information
Allow participants to join the meeting before the host arrives should be set to disabled and locked off.
Rationale:
This ensures people joining a meeting do not enter a meeting before the host has arrived. If there are annoying users, they cannot be removed or muted until the host arrives. Locking the setting ensures no one changes this when creating a meeting.
Solution
Go into the Zoom Admin Dashboard on the zoom website. Account Management -> Account Settings -> Meeting -> Scheduled Meeting -> Join before host, and ensure it is set to disabled.