ActiveRecord only saves submission for one id

I'm trying to implement permissions and roles in a rails application. I have a role model and a permission model with a has_and_belongs_to_many relationship. I'm seeding the permissions inside the database and each permission has a unique id. Inside the role model i have a method with which i can add permissions to roles and it works but active record only saves the permission with the id = 1. In the console it says that the permission is assigned but when i type Role.first.permissions it doesn't show anything. I really don't understand what i am doing wrong since i also have the user model linked to the permission model in the same way, since i want to also be able to override the roles permissions on each individual user here it works for every permission. Maybe this double linkage between permissions, roles and users is causing the problem?

Here is my role.rb:

class Role < ActiveRecord::Base
    has_and_belongs_to_many :permissions, 
                            join_table: 'roles_permissions',
                            association_foreign_key: 'role_id'

    has_many :users


    def add_permission(perm_id)
      self.permissions << Permission.find(perm_id)
    end

    def remove_all_permissions
      self.permissions.each do |i|
        i.delete(Permission.all)
      end
    end

    def remove_permission(id)
      self.permissions.delete(Permission.find(id))
    end
end

Here is my user.rb:

class User < ActiveRecord::Base
  has_and_belongs_to_many :permissions,
                          association_foreign_key: 'permission_id',
                          join_table: 'users_permissions'

  belongs_to :role      

  def add_permission(perm_id)
    self.permissions << Permission.find(perm_id)
  end

  def remove_all_permissions
    self.permissions.each do |i|
      i.delete(Permission.all)
    end
  end

  def remove_permission(id)
    self.permissions.delete(Permission.find(id))
  end
end

And here is my permission.rb:

class Permission < ActiveRecord::Base
    has_and_belongs_to_many :roles, join_table: 'roles_permissions'
    has_and_belongs_to_many :users, join_table: 'users_permissions'
end