disable translatable route object
Create a "title" function in your controller and declare it in your route, like here ( _title_callback):

entity.node_type.edit_form:
  path: '/admin/structure/types/manage/{node_type}'
  defaults:
    _entity_form: 'node_type.edit'
    _title_callback: '\Drupal\Core\Entity\Controller\EntityController::title'
  requirements:
    _permission: 'administer content types'