Attachment details bug

I have a custom taxonomy defined for object_type = ‘attachment’ (named ‘Pohoria’, see the video). When I use this extension to edit Categories and my taxonomy, this plugin puts wrongly my custom taxonomy slugs into Categories, and removes entries in my custom taxonomy. Bug is present only in “Attachment details” screen, other screens are OK. See the video attachment: https://youtu.be/1rYMrGmHPgg