Additional meeting and call-related features and issues within Microsoft Teams for business
Hi Sabina,
From what I've found, Microsoft has been rolling out enhanced co-organizer capabilities for Teams webinars, including the ability for co-organizers to edit event details (Microsoft 365 Roadmap ID 168524). However, this rollout may not yet be available in all tenants.
Based on the behavior you've described, it is possible that this capability has not yet been rolled out to your tenant, so co-organizers may still have limited editing capabilities.
Unfortunately, the webinar organizer role cannot currently be transferred to another user. If your colleagues need full management capabilities before this feature becomes available in your tenant, they may need to create a new webinar their account and use that webinar going forward.I hope this information is helpful. Let me know if you have any questions.