Diagnosing bouncer issue

I have Bouncer installed and set up. I can see in the database that my users are assigned roles and abilities, but when I try to get them, for example with auth()->user()->getRoles(), I get an empty result, and not surprisingly, authorizations in my controllers and policies fail as a result.

Silber\Bouncer\BouncerServiceProvider::class appears in my app config's providers array and my User model contains the HasRolesAndAbilities trait.

I'm using a Nova extension to see the Bouncer role and ability assignments, and it all looks good in there.

Any idea what might be preventing these permissions from being visible?