@anjas - I am betting that those users already have accounts, so they are not able to be pending on your account since technically they are already active users. They would receive an email invitation to join your account, though, and would immediately become active in your account if they accept the invitation.
Whenadding new usersto a Zoom account, those users will receive activation emails to join the Zoom account. Some users may experience issues with not receiving activation emails and are therefore unable to accept the invitation to join the account.
You can check out this article to troubleshooting filters that may cause the users to not receive the activation emails.
After you've checked IP addresses and spam filters, and confirm that users still aren't receiving activation emails, you cansubmit a requestto Zoom Support to check if the email address is on a bounce list.