Event listener fails to receive alternate events

[raviteja-b]

I am running Event listener on a machine. Event listener consistently fails to receive alternate event.

Here is my Event listener output.
server sent 3 events with ids 5,6,7 but listener recieved only 5 and 7 where as 6 is not received.
this observation is consistent even with 100 events, every alternate event is missing

python3 RedfishEventListener_v1.py
Redfish Event Listener v1.0.2
RegistryPrefixes: [""]
Connection
Keep-Alive
[{'Connection': 'Keep-Alive'}]
HttpHeaders: [{"Connection": "Keep-Alive"}]
Listening on 0.0.0.0:8080 via HTTPS
Count of Server is 1
Payload details are {"Destination":"https://9.x.x.x:8080/home/test","Context":"Public","Protocol":"Redfish"}
ServerIPList::: https://9.x.x.x
UserNameList::: root
URI is: https://9.x.x.x/redfish/v1/EventService/Subscriptions

Method = POST, status = 201, expected status = [200, 201, 204]
{'Location': '/redfish/v1/EventService/Subscriptions/3622973518', 'Strict-Transport-Security': 'max-age=31536000; includeSubdomains; preload', 'X-Frame-Options': 'DENY', 'Pragma': 'no-cache', 'Cache-Control': 'no-Store,no-Cache', 'X-XSS-Protection': '1; mode=block', 'X-Content-Type-Options': 'nosniff', 'Content-Security-Policy': "default-src 'none'; img-src 'self' data:; font-src 'self'; style-src 'self'; script-src 'self'; connect-src 'self' wss:", 'Content-Type': 'application/json', 'Date': 'Wed, 03 Mar 2021 15:04:15 GMT', 'Content-Length': '283'}
Subcription is successful for https://9.x.x.x

headers: IOrderedDict([('Host', '9.x.x.x'), ('Content-Type', 'application/json'), ('Content-Length', '224')])

bodydata: {"@odata.type":"#Event.v1_4_0.Event","Events":[{"EventId":5,"EventTimestamp":"2021-03-03T15:04:19+00:00","MemberId":0,"Message":"A Test message","OriginOfCondition":"/redfish/v1/xxx/Service"}],"Name":"Event Log"}

Server IP Address is xx.x.x.x
Server PORT number is 59404

Context (None) does not match with the server (Public).
HTTP/1.1 200 OK
Content-Length: 4

Done
response sent
Event Counter for Host 9.3.29.130 = 1

finally block - not closing the connection

headers: IOrderedDict([('Host', 'x.x.x.x'), ('Content-Type', 'application/json'), ('Content-Length', '224')])

bodydata: {"@odata.type":"#Event.v1_4_0.Event","Events":[{"EventId":7,"EventTimestamp":"2021-03-03T15:04:29+00:00","MemberId":0,"Message":"A Test message","OriginOfCondition":"/ibm/v1/xxx/Service"}],"Name":"Event Log"}