I have the same problem with Spotlight, but only with mobile users, Spotlight works perfectly for local users.
If a local user is logged on to my MacBook in the background, Spotlight also works immediately for a mobile user.
Even if I am logged in as a mobile user and log in to the terminal with su- with a local user, Spotlight works immediately.
It seems that something is not activated in MacOS when you are logged in as a mobile user. Maybe someone can do something with this information and find a solution to the problem.