Information
Change from 'Everyone' option under [Play sound for] to 'Host and co-hosts only'.
Rationale:
This option enables Host and co-hosts to know that participants are joining/leaving.
Solution
Go into the Zoom Admin Dashboard on the zoom website. Account Management -> Account Settings -> Meeting -> In Meeting (Basic) -> Sound notification when someone joins or leaves -> Play sound for -> Host and co-hosts only, and check ensure it is enabled.