3522912 - Cloud to on-premise connection to ABAP backend system due to remote host unknown during SSL handshke phase

Cloud to on-premise connection to ABAP backend system fails due to remote host unknown during SSL handshke phase:

Sample traces in ljs_trace:

2024-09-04 15:09:43,233 +0900#INFO#com.sap.scc.rt#AccessControl connection checker#          #SccEndpointValidator failed to establish connection to HTTPS://testsample:44300
java.net.SocketException: error 32 - Broken pipe (Write failed) (local port 29276 to address xx.xxx.xxx.xx (localhostname), remote host unknown)
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
    at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
    at sun.security.ssl.SSLSocketOutputRecord.flush(SSLSocketOutputRecord.java:273)
    at sun.security.ssl.HandshakeOutStream.flush(HandshakeOutStream.java:89)
    at sun.security.ssl.CertificateVerify$T12CertificateVerifyProducer.produce(CertificateVerify.java:770)
    at sun.security.ssl.SSLHandshake.produce(SSLHandshake.java:420)
    at sun.security.ssl.ServerHelloDone$ServerHelloDoneConsumer.consume(ServerHelloDone.java:182)
    at sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:376)
    at sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:479)
    at sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:457)
    at sun.security.ssl.TransportContext.dispatch(TransportContext.java:200)
    at sun.security.ssl.SSLTransport.decode(SSLTransport.java:155)
    at sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1320)
    at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1233)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:417)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:389)
    at com.sap.scc.tcs.e2e.BackendCheckHelper$TLSSecuredBackendCheckHelper.check(BackendCheckHelper.java:133)
    at com.sap.scc.tcs.e2e.HttpBackendChecker.check(HttpBackendChecker.java:58)
    at com.sap.scc.tcs.e2e.SccEndpointValidator.checkConnection(SccEndpointValidator.java:86)
    at com.sap.scc.tcs.e2e.SccEndpointValidator.checkEndpoint(SccEndpointValidator.java:72)
    at com.sap.scc.servlets.AccessControlServlet$3.run(AccessControlServlet.java:564)
    at java.lang.Thread.run(Thread.java:838)

"remote host unknown" feels a DNS resolution problem, however nslookup result shows correct resolution.

SAP Cloud Connector

KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem