roles and tags, one work the other one not

I don’t understand I have 2 roles, this 2 roles are tagged, one work, this one :

  • hosts: webservers
    sudo: yes
    roles:
  • { role: webserver, tags: [‘webserver’]}

And the other one not :

  • hosts: dbservers
    sudo: yes
    roles:
  • { role: dbserver, tags: [‘dbserver’]}

When I ran this :

ansible-playbook playbook.yml -i hosts -t dbserver

(I also try the other syntax --tags)

I’ve gto the following error :

ERROR: tag(s) not found in playbook: dbserver. possible values: adminer,common,databases,mysql,user,vhosts,webserver

As you can see the webserver tag is found, also the mysql/databases one which are in dbserver role so why my dbserver tag is not ?

Except this problem the role works fine

Thanks for your suggestions