An application server was recently upgraded to prefer TLS 1. 3, and now users are unable to connect their clients to the server. Attempts to reproduce the error...

An application server was recently upgraded to prefer TLS 1.
3, and now users are unable to connect their clients to the server. Attempts to reproduce the error are confirmed, and clients are reporting the following:
ERR_SSL_VERSION_OR_CIPHER_MISMATCHWhich of the following is MOST likely the root cause?