EM 13c: Enterprise Manager 13c Cloud Control Agent Communication with OMS Fails after Securing OMS with Third Party SSL ECC Certificate (Doc ID 2800378.1)

The Enterprise Manager 13c Cloud Control Agent is unable to communicate with the OMS server after is has been secured with a third partty SSL ECC certificate.

$ <Agent_Base_Dir>/agent_inst/bin/emctl pingOMS
Oracle Enterprise Manager Cloud Control 13c Release 4
Copyright (c) 1996, 2020 Oracle Corporation. All rights reserved.
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EMD pingOMS error: unable to connect to http server at https://<OMS_Hostname>:<OMS_Upload_portno>/empbs/upload. [handshake has no peer]

/gc_inst/em/EMGC_OMS1/sysman/log/emoms.log

2021-06-25 12:01:09,755 [SET_ADRHOME_PROPERTY] WARN emdiag.AdrMetricPropertySetter logp.251 - AdrMetricPropertySetter:run: TMCommException making remote TMClient calls
oracle.sysman.emSDK.agent.comm.exception.VerifyConnectionException: unable to connect to http server at https://<Agent_name>:<Agent_portno>/emd/main/. [handshake has no peer]
at oracle.sysman.gcagent.comm.http.ClientConnection.verifySecureConnection(ClientConnection.java:911)
at oracle.sysman.gcagent.comm.http.ClientConnection.makeConnection(ClientConnection.java:869)
at oracle.sysman.gcagent.comm.oms.http.TMClientConnection.<init>(TMClientConnection.java:96)
at oracle.sysman.gcagent.comm.oms.http.HTTPClientTerminus.connect(HTTPClientTerminus.java:252)
at oracle.sysman.gcagent.comm.oms.http.HTTPClientTerminus.sendMessage(HTTPClientTerminus.java:714)
at oracle.sysman.gcagent.comm.oms.http.HTTPClientTerminus.getReplyFromMessage(HTTPClientTerminus.java:665)
at oracle.sysman.gcagent.oms.TMRemoteClient.makeSingleRequest(TMRemoteClient.java:6692)
at oracle.sysman.gcagent.oms.TMRemoteClient.makeSingleRequest(TMRemoteClient.java:6624)
at oracle.sysman.gcagent.oms.TMRemoteClient.getActiveTargetCollection(TMRemoteClient.java:1178)
at oracle.sysman.emSDK.agent.client.TMClientFactory$Wrapper.getActiveTargetCollection(TMClientFactory.java:2643)
at oracle.sysman.core.common.emdiag.AdrMetricPropertySetter.run(EMOMSDiagConfig.java:493)
at oracle.sysman.emSDK.svc.houseKeeping.HouseKeepingTask.run(HouseKeepingService.java:168)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
Caused by: javax.net.ssl.SSLHandshakeException: handshake has no peer
at oracle.sysman.gcagent.comm.http.BaseHttpsContext.verifyConnection(BaseHttpsContext.java:130)
at oracle.sysman.gcagent.comm.http.BaseHttpsContext.verifyConnection(BaseHttpsContext.java:111)
at oracle.sysman.gcagent.comm.http.ClientConnection.verifySecureConnection(ClientConnection.java:894)
... 13 more
Caused by: javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated