Problem

When an attachment is deleted from the Attachments section of the page. It causes its reference on the pages to become unknown attachments. 

Environment

7.19.21, 8.9.0

Steps to Reproduce

1. Attach a file to the page. 
2. While viewing the page go to "..." > Attachments, and remove the attachment
3. The attachment will be removed but its reference on the page shows an Unknown attachment
4. 

Expected Results

The Attachment and its reference should be deleted.  Whenever user wants to delete attachments in bulk its preferable to remove them from the attachments section as they can bulk select and delete. Users should be given the option to remove Unknown attachments in bulk. 

Actual Results

Attachment gets removed. On the page, the attachment reference becomes " ? Unknown attachment"

Workaround

Edit the page >> Select the attachment and Delete