Microsoft Exchange 2013 iApp - Can't login to OWA or ECP if more than one server is active in pool

LogonFormat : PrincipalName ClientAuthCleanupLevel : High LogonPagePublicPrivateSelectionEnabled : False LogonPageLightSelectionEnabled : False FilterWebBeaconsAndHtmlForms : UserFilterChoice NotificationInterval : 120 DefaultTheme : UserContextTimeout : 60 ExchwebProxyDestination : VirtualDirectoryType : OwaVersion : Exchange2013 ServerName : Server1 InstantMessagingCertificateThumbprint : InstantMessagingServerName : RedirectToOptimalOWAServer : True DefaultClientLanguage : 0 LogonAndErrorLanguage : 0 UseGB18030 : False UseISO885915 : False OutboundCharset : AutoDetect GlobalAddressListEnabled : True OrganizationEnabled : True ExplicitLogonEnabled : True OWALightEnabled : True DelegateAccessEnabled : True IRMEnabled : True CalendarEnabled : True ContactsEnabled : True TasksEnabled : True JournalEnabled : True NotesEnabled : True RemindersAndNotificationsEnabled : True PremiumClientEnabled : True SpellCheckerEnabled : True SearchFoldersEnabled : True SignaturesEnabled : True ThemeSelectionEnabled : True JunkEmailEnabled : True UMIntegrationEnabled : True WSSAccessOnPublicComputersEnabled : True WSSAccessOnPrivateComputersEnabled : True ChangePasswordEnabled : True UNCAccessOnPublicComputersEnabled : True UNCAccessOnPrivateComputersEnabled : True ActiveSyncIntegrationEnabled : True AllAddressListsEnabled : True RulesEnabled : True PublicFoldersEnabled : True SMimeEnabled : True RecoverDeletedItemsEnabled : True InstantMessagingEnabled : True TextMessagingEnabled : True ForceSaveAttachmentFilteringEnabled : False SilverlightEnabled : True PlacesEnabled : False AllowCopyContactsToDeviceAddressBook : True AnonymousFeaturesEnabled : True IntegratedFeaturesEnabled : True DisplayPhotosEnabled : True SetPhotoEnabled : True PredictedActionsEnabled : False UserDiagnosticEnabled : False ReportJunkEmailEnabled : True WebPartsFrameOptionsType : SameOrigin AllowOfflineOn : AllComputers SetPhotoURL : InstantMessagingType : None Exchange2003Url : FailbackUrl : LegacyRedirectType : Silent Name : owa (Default Web Site) InternalAuthenticationMethods : {Basic, Fba} MetabasePath : IIS://Server1.domain.com/W3SVC/1/ROOT/owa BasicAuthentication : True WindowsAuthentication : False DigestAuthentication : False FormsAuthentication : True LiveIdAuthentication : False AdfsAuthentication : False OAuthAuthentication : False DefaultDomain : GzipLevel : Low WebSite : Default Web Site DisplayName : owa Path : D:\Program Files\Microsoft\Exchange Server\V15\FrontEnd\HttpProxy\owa ExtendedProtectionTokenChecking : None ExtendedProtectionFlags : {} ExtendedProtectionSPNList : {} AdminDisplayVersion : Version 15.0 (Build 913.22) Server : Server1 InternalUrl : https://outlookweb.domain.com/owa ExternalUrl : https://outlookweb.domain.com/owa ExternalAuthenticationMethods : {Fba} AdminDisplayName : ExchangeVersion : 0.10 (14.0.100.0) DistinguishedName : CN=owa (Default Web Site),CN=HTTP,CN=Protocols,CN=Server1,CN=Servers,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=MyCompany,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=mycompany,DC=edu Identity : Server1\owa (Default Web Site) Guid : ae94edc4-9bce-4362-836a-02c1cc3577ac ObjectCategory : domain.com/Configuration/Schema/ms-Exch-OWA-Virtual-Directory ObjectClass : {top, msExchVirtualDirectory, msExchOWAVirtualDirectory} WhenChanged : 7/1/2014 8:22:23 AM WhenCreated : 6/30/2014 10:50:18 AM WhenChangedUTC : 7/1/2014 12:22:23 PM WhenCreatedUTC : 6/30/2014 2:50:18 PM OrganizationId : OriginatingServer : mydc.domain.com IsValid : True ObjectState : Changed