Reminder emails 1 week/day/hour not sent

Hi

My case is as follows:
I have 3 webinars scheduled.
I created a webinar in Zoom for the first scheduled date.
The person who registered for the first one wanted his registration to be active for all 3 webinars.
After the end of the first webinar I edited the date of the next one so he could attend the second webinar without new registration.
Everything worked well but there was a problem because the person did not receive any reminder email before the second webinar. There was marked to send email 1day and 1 hour before new date, but system didn't send it.
Is this a bug in the Zoom system? Or should I solve such case  in a different way?
Unfortunately I have not found a way to manually send a reminder from Zoom.