Selector bulk action missing
I've finally found a solution. 

I needed to go to Views/Media and add Bulk update to the Fields, but it was missing. Once I realised that I needed to restore it I found this drush command.

* drush cim --yes --partial --source=core/modules/media/config/optional &amp;&amp; cr


Which updates the following:

+------------+--------------------------------------+-----------+
| Collection | Config                               | Operation |
+------------+--------------------------------------+-----------+
|            | system.action.media_delete_action    | Create    |
|            | system.action.media_publish_action   | Create    |
|            | system.action.media_save_action      | Create    |
|            | system.action.media_unpublish_action | Create    |
|            | views.view.media                     | Update    |
+------------+--------------------------------------+-----------+


Then clear cache and Bulk update has now been restored to the Fields section.