Users could access sharepoint intranet site and internet site using the domain friendly names. Now they can access intranet site and internet site using IP addresses only. Further, when they access the site, it not possible for them to make edits to calendar or change content, upload documents, etc. As sys admin I make the changes on their behalf directly on the SharePoint WFE. I was advised to take a look at AAM on Central Admin. 2 screenshots attached. One shows what the user sees when they attempt to make changes, e.g. to calendar. The second screenshot shows current AAM settings on server. Please advice how to resolve this issue. Thank you in advance. (FYI - I cannot pinpoint what may have caused this issue to being with).