Additional features, settings, or issues not covered by specific Microsoft Teams categories
Hello Stefania
I am V. Arya, Independent Advisor, to work with you on this issue. As a first level of troubleshooting, please try in Web Teams (Edge/Chrome browsers) and let me know whether it works there or not to advise you on further steps.
Assuming you are using Teams app on Wndows 10 - Try to clear cache of Teams
Close Microsoft Teams app
Press Windows key, hold it and press r
Paste the following into Run Window
%appdata%\Microsoft\teams
Copy everything from this folder to some other place in your computer. Hence, it means that you will have a backup.
Now delete everything within this folder
Open Microsoft Teams app and now check