On further investigation this seems to be possibly related to CSRF issues. In a load balanced environment would calling the automation web service that loads cause CSRF issues if machine switches between request.
I tried disabling CSRF protection but this didn't seem to fix the issue. The error I am seeing in the error logs is as follows.
Message: The CSRF hidden field value didn't match the CSRF cookie value.
Exception type: CMS.Protection.Web.UI.CsrfException
Stack trace:
at CMS.Protection.Web.UI.CsrfProtection.ValidateCsrfTokens(Byte[] cookieToken, Byte[] hiddenFieldToken)
at CMS.Protection.Web.UI.CsrfProtection.OnPostMapRequestHandlerExecute(Object sender, EventArgs eventArgs)
at CMS.Base.AbstractHandler.CallEventHandler[TArgs](EventHandler 1 h, TArgs e)
at CMS.Base.AbstractHandler.Raise[TArgs](String partName, List 1 list, TArgs e, Boolean important)
at CMS.Base.SimpleHandler 2.RaiseExecute(TArgs e)
at CMS.Base.SimpleHandler 2.RaiseExecute(TArgs e)
at CMS.Base.SimpleHandler 2.StartEvent(TArgs e)
at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)