Scope conflict when joining one table, what to do?

Question

Ruby on Rails

In the model of tasks with users, there are 2 connections.

belongs_to :initiator, :class_name => 'User', :foreign_key => 'initiator_id'
belongs_to :designer, :class_name => 'User', :foreign_key => 'designer_id'

And two scope

scope :initiator_filter, ->(name){ joins(:initiator).where("users.name LIKE ?", "%#{name}%")  unless name.nil? }
 scope :designer_filter, ->(name){ joins(:designer).where("users.name LIKE ?", "%#{name}%")  unless name.nil? }

When working separately, both of them work.
Together a conflict arises and the latter works.
This is due to join on the same table, but I don't know how to fix it.(

Answer 1

joins('users initiators on initiators.id = initiator_id').where('initiators.name LIKE ...')

Answer 2

The only join must be put in front

joins('LEFT JOIN users designers on designers.id = designer_id')