Hi, when multiple users are experiencing the same issue there's usually a service degradation. Either in your org. infrastructure or in the Teams service. I can't view the second image but suggest you open up a support ticket with Microsoft. While that is being processed you can try some standard troubleshooting such as signing out manually, removal/reinstall and/or clear cache. You can also verify the behavior using Teams on the web, bear in mind that you'll need Chrome or Edge for screen sharing.