Store user data in auth server or resource server? Or both?

Question

This is my first time setting up OpenID Connect with IdentityServer 4 and AspNetIdentity and I was hoping someone could demystify the part about storing user data.

What I've read so far is that user data should be stored in the Auth db that is connected to the auth server, but I'd really like to store user data in the resource db too that is connected to the resource server.

I currently have a data model that looks like this:

I have omitted many of the fields for both User and Event, but you hopefully get the picture. We have a User table, an Event table, and a Host table. A User can Host an Event. The many-to-many relation between a User and an Event is via the Host table.

This is such a rudimentary question on architecture, yet it's really hard to find a good answer that makes sense and that isn't a total hack. So far I've read about the following solutions from different people:

1. Store all user data in the Auth db, only, and then set an API up on the Auth server so the Resource server can get data from the Auth server.

2. Someone else says that non-auth related data such as a user's city or country should not be stored in the Auth db. Instead keep auth related data in the Auth server only and any user-related data in the Resource DB. This sounds like the two User records need to be in sync? Sounds like a bad idea.

3. Have the Resource server and Auth server be one application so that we can build the necessary relations between User, Host, and Event. But this seems to defeat the whole purpose of using OpenID Connect.

So what is the standard architecture here? Or if there is no one-size-fits all, how would you store this user data?