Alternative Host Cannot Join and Does not get Invite or Upcoming Meetings

This STILL seems an issue.

We have an Enterprise license for a very large company. I host Software training meetings. I went into my “upcoming meetings” a week before. I named an “alternative host” who also is on the enterprise license. He did NOT receive an email. I forwarded him the email link that I “copied” from the meeting details. He clicked on it, and it prompted him to register, then said “host cannot register”, The meeting he is named as Alternative Host does NOT show in his upcoming meetings. Very frustrating when you are trying to have a back up instructor step in for you. 

Does Zoom have any reasonable resolution for this? Is there some work around?