Kie server client load balancer using wrong URL under concurrent access

We recently moved both the kie server jar and the kie client jar to 7.4.1 (from 6.4)
After this change what we are noticing is that we sometimes see a spike in kieserver 404s due the kie-server-client jar 'post'ing on incorrect urls

For e.g. when it is working ok, it posts on this url:
https://kieserver.company.com/kie-server/services/rest/server/containers/instances/kie_container
but when it is having "issues" it starts posting to this url (notice the duplicate "containers/instances/kie_container"")
https://kieserver.company.com/kie-server/services/rest/server/containers/instances/kie_container/containers/instances/kie_container

Restarting the client application seems to fix it.

The exact stack trace I see is as below

org.kie.server.api.exception.KieServicesHttpException: Unexpected HTTP response code when requesting URI 'https://kieserver.company.com/kie-server/services/rest/server/containers/instances/kie_container/containers/instances/kie_container'! Error code: 404, message:
at org.kie.server.client.impl.AbstractKieServicesClientImpl.createExceptionForUnexpectedResponseCode(AbstractKieServicesClientImpl.java:617)
at org.kie.server.client.impl.AbstractKieServicesClientImpl.makeHttpPostRequestAndCreateServiceResponse(AbstractKieServicesClientImpl.java:290)
at org.kie.server.client.impl.AbstractKieServicesClientImpl.makeHttpPostRequestAndCreateServiceResponse(AbstractKieServicesClientImpl.java:268)
at org.kie.server.client.impl.RuleServicesClientImpl.executeCommandsWithResults(RuleServicesClientImpl.java:48)

This issue comes when we have only one url as availableendpoints. In case of exception url is marked as offline and before url comes back online second failure add url with containers/instances/kie_container as failedendpoints and next time that url would be mark as online. I am able to reproduce this issue with kie 7.4.1
Here is the git repo to reproduce this issue :

https://github.intuit.com/mbhalodi/KieServiceClientTest

Also I tested this issue with below fix and it works :

@Override
public String markAsOffline(String url) {
checkEmpty(availableEndpoints);
synchronized (availableEndpoints) {

checkEmpty(availableEndpoints);*
String baseUrl = locateUrl(availableEndpoints, url);
availableEndpoints.remove(baseUrl);
return baseUrl;
Just need to check if availableEndpoints is not null before marking it as offline. Please let me know if you need more details from myside.