FoundationDB 5.1, 3 node cluster with TLS.
Plugin and binaries were built using 5.1 tag from github.
Can see a lot of handshake errors in the logs:
/var/log/foundationdb/trace.192.168.001.001.4500.1526050130.z1HPr4.1.xml:<Event Severity="20" Time="1526050448.022894" Type="N2_ReadError" Machine="192.168.1.1:4500" ID="b58c31d6bbea2863" Message="2" SuppressedEventCount="2" logGroup="default"/>
/var/log/foundationdb/trace.192.168.001.001.4500.1526050130.z1HPr4.1.xml:<Event Severity="10" Time="1526050448.022894" Type="TLSConnectionRecvError" Machine="192.168.1.1:4500" ID="b58c31d6bbea2863" Error="connection_failed" ErrorDescription="Network connection failed" ErrorCode="1026" logGroup="default"/>
/var/log/foundationdb/trace.192.168.001.001.4500.1526050130.z1HPr4.1.xml:<Event Severity="10" Time="1526050448.022894" Type="FDBLibTLSHandshakeError" Machine="192.168.1.1:4500" ID="b58c31d6bbea2863" LibTLSErrorMessage="handshake failed: unexpected EOF" logGroup="default"/>
/var/log/foundationdb/trace.192.168.001.001.4500.1526050130.z1HPr4.1.xml:<Event Severity="10" Time="1526050448.022894" Type="TLSConnectionHandshakeError" Machine="192.168.1.1:4500" ID="b58c31d6bbea2863" logGroup="default"/>
/var/log/foundationdb/trace.192.168.001.001.4500.1526050130.z1HPr4.1.xml:<Event Severity="10" Time="1526050448.022894" Type="ConnectionFrom" Machine="192.168.1.1:4500" ID="b58c31d6bbea2863" FromAddress="192.168.1.2:55080:tls" SuppressedEventCount="1" logGroup="default"/>