Released: 2024 H1 Cumulative Update for Exchange Server

After the installation CU14 on the dev and prod servers we register increased number of 401 errors in the IIS logs and they are mostly related to EWS.

Test-OutlookWebServices is Failing for both EWS and OAB and details show 401 error. Disabling Extended Protection did not help.

Remote Connectivity Analyzer did not report any issue (EWS test). Do you have similar experience/would you suggest me some solution? Thanks in advance!

RunspaceId          : 82f4a5dd-1dea-46cc-b176-9f3a7e7bf177
Source              : server1.domain.local
ServiceEndpoint     : server2.domain.local
Scenario            : ExchangeWebServices
ScenarioDescription : Exchange Web Services
Result              : Failure
Latency             : 12
Error               : System.Net.WebException: The remote server returned an error: (401) Unauthorized.
                         at System.Net.HttpWebRequest.GetResponse()
                         at Microsoft.Exchange.Management.SystemConfigurationTasks.ServiceValidatorBase.InternalInvoke(
                      )
                         at Microsoft.Exchange.Management.SystemConfigurationTasks.ServiceValidatorBase.Invoke()
Verbose             : [2024-02-28 14:49:28Z] Exchange Web Services connecting to 'https://server2.domain.local/ews/Exc
                      hange.asmx'.
                      [2024-02-28 14:49:28Z] Test account: CasConnectivityUser Password: ******
                      [2024-02-28 14:49:28Z] Exchange Web Services request:
                      Content-Type: text/xml;charset=utf-8
                      User-Agent: SERVER1/Test-OutlookWebServices/TestCasConnectivityUser@domain.local
                      X-ExCompId: Management.ServiceValidator
                      Accept: text/xml
                      Authorization: Negotiate xxxx
                      Host: server2.domain.local
                      Content-Length: 746
                      Expect: 100-continue
                      [2024-02-28 14:49:28Z] Exchange Web Services request:
                      <?xml version="1.0" encoding="utf-8" standalone="yes"?>
                      <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:m="http://schemas.micr
                      osoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/service
                      s/2006/types" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                        <soap:Header>
                          <t:RequestServerVersion Version="Exchange2007_SP1" />
                        </soap:Header>
                        <soap:Body>
                          <m:ConvertId DestinationFormat="OwaId">
                            <m:SourceIds>
                              <t:AlternateId Format="EntryId" Id="xxxx==" Mailbox="email address removed for privacy reasons" />
                            </m:SourceIds>
                          </m:ConvertId>
                        </soap:Body>
                      </soap:Envelope>
                      [2024-02-28 14:49:28Z] Exchange Web Services response:
                      request-id: d4a34a43-9b09-4a9d-9c17-6217f2dd6d11
                      X-OWA-Version: 15.2.1544.4
                      Server: Microsoft-IIS/10.0
                      WWW-Authenticate: Negotiate,NTLM,Basic realm="server2.domain.local"
                      X-Powered-By: ASP.NET
                      X-FEServer: SERVER2
                      Date: Wed, 28 Feb 2024 14:49:27 GMT
                      Content-Length: 0
                      [2024-02-28 14:49:28Z] Exchange Web Services response:
                      System.Net.WebException: The remote server returned an error: (401) Unauthorized.
                         at System.Net.HttpWebRequest.GetResponse()
                         at Microsoft.Exchange.Management.SystemConfigurationTasks.ServiceValidatorBase.InternalInvoke(
                      )
                         at Microsoft.Exchange.Management.SystemConfigurationTasks.ServiceValidatorBase.Invoke()
MonitoringEventId   : 6002