Dear Marleen Galligan
Good day!
Thank you for posting to Microsoft Community. We are glad to assist!
I'm sorry to hear about the issues you're experiencing with your Teams channel notes. It sounds quite frustrating; indeed, to isolate the issue and identify root cause, may we confirm below information
Based on your description regarding "All our Channel Notes have disappeared" i did discuss with our online technical team and based on the above scenario, its best for issue to be handled by our online technical team to further investigated as they have higher permission compared to us in Microsoft forum community. A support Engineer can further connect with you remotely, for further troubleshooting and involve the backend team where need be, they may request some logs for further analysis. Please understand that as public forum support, we don’t have higher permissions to check and analyze these logs and considering your scenario maybe inconveniencing, to quickly help assist, kindly contact your organization admin or you can create a service request to report this symptom to our online channel. Here is contact support document: Get support - Microsoft 365 admin | Microsoft Learn If you need guidance on how to find your admin, see How do I find my Microsoft 365 admin? - Microsoft Support
In case of any further query, we will be on standby
Have a great day