If the new Microsoft Teams is not behaving correctly, there is a couple of things you can try to rectify the issue. You do not need an IT administrator to perform these steps.

1. Type apps into the taskbar search box.

2. You will see the system settings Apps & features. Click on this to open.

3. In the Apps & features section, type teams into the search field. You will see Microsoft Teams (Work & School) appear in the list.

4. Click on Microsoft Teams and it will expand like the image below. Click on Advanced options.

5. Scroll down until you see the heading Reset. Here you have two options.

6. Try the Repair option first. This will attempt to fix issues with the app without removing account information from the application.

7. If the Repair fails, try the Reset option next. This will completely reinstall the application removing any cache information and credentials. This means you will need to log in to Teams as if it was the first time once it has finished.

If neither of these steps resolves your issue, please contact the IT helpdesk.