UE 5.7 City Sample broken

It seems that the City Sample project is broken under Unreal Engine 5.7.

Traffic and Crowd are not working, I get errors like:

LogMassSpawner: Error: No locations found on zone graphs

The map “MassCrowd” under the AI folder, works without issues.

Is this a known problem with 5.7? I downloaded the project from scratch as it was tagged to be compatible with 5.7, but I have no traffic and no crowd.

Apparently I had to manually run the Build command inside the actor CityTrafficBuilder_BP, never happened before.