Additional features, settings, or issues not covered by specific Microsoft Teams categories
Hello WilsonBain,
From your description, you cannot get the email address of the channel or change the team picture. For the newly created team and channel, it may take some time to sync to server. So please wait several hours and then check again.
If you still get the same error, as a temporary workaround, I suggest you contact the Office 365 admin to create new teams or channel in Microsoft Teams admin center. For more information about how to create new teams and channels, please see: Manage teams in the Microsoft Teams admin center. After creating them in the admin center, please check whether you can get the email address and change the picture.
If the issue still persists, to better help you, please provide the following information to me:
1. Whether other members in your organization have the same problem.
2. I'd like to collect the Debug logs for further analysis. To collect the logs, please see: Debug logs. After getting the logs, please send to me via Private Message.
Regards,
Seven