Summary

• Cannot delete pinned comment in an attachment. Check video: pincomment.mp4

Steps to Replicate

• Attach a file in a page
• Click on the attachment while in view mode
• In the bottom we have the Drag this pin to add a comment
• Drag it to the attached file
• Add a comment: "Test"
• Click on the . . . option in the comment on the right
• Click on Delete

Expected Results

• Comment deleted

Actual Results

• Nothing happens

Side notes

• Resolving the comment is not a workaround/solution as it will persist in the attachment and is not deleteable too. You can hide it though.
• It is possible to delete any further comment (feedback) that references the first comment.