How to create a calendar event for an existing Teams meeting

I have a Teams meeting URL that I’d like to add to my calendar.
When I create a new event and chose online meeting, I put the URL in the description…saving the event generates a JoinUrl null error.
If I don’t put the url in the description, I get a default teams meeting. Changing the URL to mine, it still takes me to the default meeting when selecting Join Online Meeting from the event.