[Plugin: WP Easy Post Types] Adding custom columns to post list gets removed when saving post type

Here’s how to recreate the problem:
– use add_filter(‘manage_edit-<custom_post_type>-columns’, callback)
to add extra columns to the main listing of a custom post type
(example here: https://pastebin.com/dU9cNTfk)
– observe that the list includes the new column
– go to the edit screen for the custom post type and hit the “Save” button
– observe that the list no longer includes the new column

Any more information I can provide, please let me know.