Upgraded plan to 500 attendees and paid but it still only allows for 100

Hi! I upgraded my account last night to allow for 500 attendees, paid the fee and it says my account has it, but when I went to facilitate a session today it was giving issues and only allowed for 100 people in the room. Has anyone else had this issue and how do we resolve it?

I pre-created the meetings before I had the upgraded version but I thought that it would apply to all meetings once I upgraded. Let me know if anyone has an ideas as I need the 500 capacity by tomorrow morning.

Thank you!