EWS email move stopped working

We currently use EWS to move emails from the inbox of one mailbox to the inbox on another mailbox based on specified criteria. The code is as follows:

private void MoveEmailToAttacherMailbox(string id, string attacherMailbox)
    {
      DocStore.Logger.Info(string.Format("{0} id: {1} To attacherMailbox: {2}", (object) nameof (MoveEmailToAttacherMailbox), (object) id, (object) attacherMailbox));
      try
      {
        Item.Bind(this.exchangeService, (ItemId) id).Move(new FolderId(WellKnownFolderName.Inbox, (Mailbox) attacherMailbox));
      }
      catch (Exception ex)
      {
        ProjectData.SetProjectError(ex);
        Exception exception = ex;
        DocStore.Logger.WarnException(nameof (MoveEmailToAttacherMailbox), exception);
        ProjectData.ClearProjectError();
      }

Unfortunately since 29th November we have been getting an error: "MoveEmailToAttacherMailbox Microsoft.Exchange.WebServices.Data.ServiceResponseException: The move or copy operation failed."

No permissions have changed and the mailbox we are moving from has full delegate permissions to the mailbox we are moving to. Any assistance will be greatly appreciated.
Martin HolmesAsked:
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AmitIT ArchitectCommented:
I advise you to check iis logs, look for error code for both accounts, it can help you to find the cause, you can also restart iis or server and check again. Lot of time simple restart fixes several issues.
Martin HolmesAuthor Commented:
Hi, we use O365 so do not have access to IIS logs. Will there be any logs anywhere in the O365 admin portal i can check?
AmitIT ArchitectCommented:
Open case with office 365 team.
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