I've had this issue for over a year. When I drag multiple images to attach to a comment, only one image will be attached the first time I try that. I have to then delete the image, and retry with multiple images, which may or may not work, but often does. Why can't I attach multiple images straight away?
Sidenote: I wouldn't have to edit a comment, attach images, and save it again if I could attach images while commenting on marking a ticket DONE.