
The phone number calling you will always be Zoom-owned phone number.
Ensure the call-out phone numbers in the account are not blocked by your phone service.
Make sure your meeting or webinar role has permission to use call-out to join audio by phone or invite others. Setting is enabled at the account, group, or user level. Prerequisites for joining meeting or webinar audio by phone "Call me" also doesn't work if the meeting is scheduled with "No Fixed Time.". "Call me" does not work if you call more than 15 minutes before the start of a meeting. Alternatively, you can manually dial into the meeting. While in a meeting or webinar, you can call yourself (also known as "call me") to join audio by phone.