According
sdk-nrf/subsys/nrf_security/Kconfig.tls - config MBEDTLS_SSL_DTLS_CONNECTION_ID
"The Connection ID extension is still in draft state."
Since March 2022 it's not longer a draft it's a Proposed Standard.
Therefore consider to update that text (after 2 years) into
"The Connection ID extension is specified in RFC 9146".