I have been trying out the Pipeline Githubnotify Step Plugin as part of notifying pull requests to a repo in a GitHub Enterprise environment.  If I do not specify the credentialsId then the plugin reports back to GitHub Enterprise fine. But the following is reported at the end of the pipeline job processing:

java.lang.IllegalArgumentException: The suplied credentials are invalid to login

at org.jenkinsci.plugins.pipeline.githubstatusnotification.GitHubStatusNotificationStep.getGitHubIfValid(GitHubStatusNotificationStep.java:234)

at org.jenkinsci.plugins.pipeline.githubstatusnotification.GitHubStatusNotificationStep.getRepoIfValid(GitHubStatusNotificationStep.java:239)

at org.jenkinsci.plugins.pipeline.githubstatusnotification.GitHubStatusNotificationStep.access$100(GitHubStatusNotificationStep.java:75)

at org.jenkinsci.plugins.pipeline.githubstatusnotification.GitHubStatusNotificationStep$Execution.run(GitHubStatusNotificationStep.java:344)

at org.jenkinsci.plugins.pipeline.githubstatusnotification.GitHubStatusNotificationStep$Execution.run(GitHubStatusNotificationStep.java:326)

at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)

at hudson.security.ACL.impersonate(ACL.java:213)

at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)

at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)

at java.util.concurrent.FutureTask.run(FutureTask.java:266)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

Finished: FAILURE

If I specify credentialsId in the Jenkinsfile for githubNotify then the same error is reported on the initial call to githubNotify.  I checked the connection using these credentials on the pipeline-syntax githubNotify sample step and it reports that the suplied credentials are invalid.  However, these credentials are not invalid as I have tested them on our GutHub Enterprise environment.  What I think may be happening is that the plugin is defaulting to checking the credentials against GitHub rather than GitHub Enterprise when the API Endpoint is supplied?