Hi,

You are currently using TLSv1/SSLv3 ECDHE-RSA-AES256-GCM-SHA384 256 Teams stopped TLSv1/ TLSv1.1 and only allowing TLS1.2+

So change your TLS settings to enforce it only

method = TLSv1.2+

after restarting kamailio your teams connections should be good.