3214501 - "connection refused" error happens intermittently using FTP adapter with FTPS protocol in CPI

You see error below intermittently while sending message to an FTP server through FTP adapter using FTPS protocol:

com.sap.it.rt.adapter.http.api.exception.HttpResponseException: An internal server error occured: error 111 - Connection refused (Connection refused) (local port <port> to address <IP> (vsaxxx.od.sap.biz), remote port <port> to address <IP> (<hostname>)).

In LJS logs you can see similar as below:

<timestamp>#+00#TRACE#com.sap.esb.camel.ftp.client.SapFTPSClient##<credential>#https-jsse-nio-8041-exec-14###aff458a1f#na#na#na#na#Sending command: EPSV|
<timestamp>#+00#TRACE#com.sap.esb.camel.ftp.client.SapFTPSClient##<credential> #https-jsse-nio-8041-exec-14###aff458a1f#na#na#na#na#EPSV received response code 229|
<timestamp>#+00#WARN#com.sap.esb.camel.ftp.sap.ftp.component.SapFtpProducer##<credential> #https-jsse-nio-8041-exec-14###aff458a1f#na#na#na#na#Writing file failed with: File operation failed: 234 AUTH TLS OK starting TLS negotiation
<timestamp>#+00#DEBUG#com.sap.esb.camel.ftp.sap.ftp.component.SapFtpProducer##<credential> #https-jsse-nio-8041-exec-14###aff458a1f#na#na#na#na#Disconnecting from: sap-ftps://<hostname>:<port><path><parameters>
<timestamp>#+00#TRACE#org.apache.camel.component.file.remote.FtpsOperations##<credential>#https-jsse-nio-8041-exec-14###aff458a1f#na#na#na#na#Client logout|

• Cloud Integration
• SAP Integration Suite

SAP HANA Cloud Integration, SAP HCI, SAP CPI, SCPI, SFSF, tenant, iFlow, Integration Flow, deployment, FTP, FTPS, adapter, channel, sftp, configuration, connection, refused, error, intermittently, protocol, internal, server, error 111, , KBA , LOD-HCI-PI-CON-SOAP , SOAP Adapter , Problem