Hi José,
On a given environment, you have applicational users (user provider Users) and infrastructure users (user provider Service Center). Modules by default have Users as their User Provider:

By default, multi-tenant tables only expose information for their tenant, meaning that in a module with User Provider Users, you would only see information from applicational users, hence your query would not have the information from Service Center users. You can change that by choosing to Show Tenant Identifier option, on tab Advanced, after double clicking the option More... on the MultiTenant entities like User or User_Role. When the option is checked, they become red and the multitenant ones are the ones with a vertical bar on the left symbol.

Given the aforementioned, if you activate this option for the User_Role and User entity, you should be ready to go.
Tenant with id 1 is usually Service Center (it is the first one to be created) but you have the Tenant table to join and see the Tenants.
Hope it helps.
Regards,
João