SSMS IntelliSense not working with sa user

In SSMS (versions 17 and 18), IntelliSense is not working with the sa user, but it is working with another user. If I connect to a SQL database with the sa user and create a query window, IntelliSense does not work in this window. However, if I make a second connection to the same database with another user and create a query window, IntelliSense works. If change back to the query window with sa user, IntelliSense again does not work.