During January 2026, Multiarc enhanced TLS 1.3 session resumption reliability on Linux within the dotnet/runtime repository. Focusing on back end development and network programming in C#, Multiarc implemented correct issuance and reuse of session tickets and improved client certificate handling for resumed connections. The work addressed Linux-specific handshake failures and strengthened security protocols by ensuring accurate mutual authentication reporting for resumed TLS sessions. Automated tests were added to provide end-to-end coverage of these cryptographic flows. This contribution demonstrated a deep understanding of security-sensitive code paths and improved the stability and security of TLS 1.3 on Linux platforms.