Connection closed unexpectedly

Question

I'm trying to move a Tomcat8 webapp from a Windows environment to RHEL 7.

Everything works out fine except one thing. There is a webservice that the webapp is requesting info from and in Windows it works flawlessly, but on the RHEL 7 it throws error below.

I believe there is a configuration error or perhaps a firewall/SELinux-issue on the RHEL 7, but I see nothing in any log.

Any ideas are welcome:-)

2022-02-11 16:24:00,826 INFO  [Thread-14] http.HTTPSender (HTTPSender.java:196) - Unab
le to sendViaPost to url[https://integrationplatform.i.domain.se:8181/PS/IP/service.svc]
2022-02-12 10:40:01,370 ERROR [Thread-28] start.StartUI$CallPaxis (StartUI.java:1528) - 
Connection or outbound has closed
org.apache.axis2.AxisFault: Connection or outbound has closed
    at org.apache.axis2.AxisFault.makeFault(AxisFault.java:430)
    at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:78)
    at org.apache.axis2.transport.http.AxisRequestEntity.writeRequest(AxisRequestEntity.java:84)
    at org.apache.commons.httpclient.methods.EntityEnclosingMethod.writeRequestBody(EntityEnclosingMethod.java:499)
    at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2114)
    at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)        
    at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
    at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
    at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
    at org.apache.axis2.transport.http.AbstractHTTPSender.executeMethod(AbstractHTTPSender.java:621)
    at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:193)
    at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
    at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:404)
    at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:231)
    at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:443)
    at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:406)
    at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:229)
    at org.apache.axis2.client.OperationClient.execute(OperationClient.java:165)
    ....
    at java.lang.Thread.run(Unknown Source)
Caused by: com.ctc.wstx.exc.WstxIOException: Connection or outbound has closed
    at com.ctc.wstx.sw.BaseStreamWriter.finishDocument(BaseStreamWriter.java:1692)
    at com.ctc.wstx.sw.BaseStreamWriter.close(BaseStreamWriter.java:288)
    at 
org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper.close(XMLStreamWriterWrapper.java:46)
    at org.apache.axiom.om.impl.MTOMXMLStreamWriter.close(MTOMXMLStreamWriter.java:188)
    at org.apache.axiom.om.impl.llom.OMSerializableImpl.serializeAndConsume(OMSerializableImpl.java:197)
    at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:74)
    ... 20 more
Caused by: java.net.SocketException: Connection or outbound has closed
    at sun.security.ssl.SSLSocketImpl$AppOutputStream.write(Unknown Source)
    at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
    at java.io.BufferedOutputStream.flush(Unknown Source)
    at org.apache.commons.httpclient.ChunkedOutputStream.flush(ChunkedOutputStream.java:191)
    at com.ctc.wstx.io.UTF8Writer.flush(UTF8Writer.java:99)
    at com.ctc.wstx.sw.BufferingXmlWriter.flush(BufferingXmlWriter.java:214)
    at com.ctc.wstx.sw.BufferingXmlWriter.close(BufferingXmlWriter.java:194)
    at com.ctc.wstx.sw.BaseStreamWriter.finishDocument(BaseStreamWriter.java:1690)
    ... 25 more