Hello Hermann,
Thank you for your question in the Symphony Forums.
After initialling reviewing your questions on the internet - it seems the issue might be more on the configuration of the SQL side. Most articles do point towards ensuring that you are enforcing all connections on your application with at least TLS 1.2.
Depending on the current configurations you are using at the moment it may fall back to a lower version of TLS 1.x - so you will need to make sure that all existing and future connections are TLS 1.2.
With security cipher protocols - it is advised to use TLS 1.2 - I have provided a example on the minimum configuration that Symphony related components would accept. You can review your existing congifuration and check if they are compliant.
--server.ssl.enabled-protocols=TLSv1.2
--server.ssl.protocol=TLS
--server.ssl.ciphers=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Please let us know should you have any further questions or feedback.