Dear Leonardo Mariano2
Good day!
Thank you for posting to Microsoft Community. We are glad to assist!
Based on your description, I understand you concern with stopping New Teams from popping up.
May I know whether you have updated the latest version of Teams Version update history for Teams app deployments - Office release notes | Microsoft Learn?
May I double confirm whether you have turned off Chat message notifications?
In the meanwhile, you may have a try to clear the cache, refer to Clear Teams cache - Microsoft Teams | Microsoft Learn.
If the issue still persists, please feel free to let me know, I will continue to assist you.
Please note that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Thanks for your precious time and your understanding would be highly appreciated. Have a nice day!
Best regards,
Allen | Community Moderator