I'm not sure this is a bug, for me it looks like an expected behaviour. Why would the annotation behave differently after opening the delete dialog and cancelling any action? Was it different in previous versions?
From what I understand, the side improvement you mention is the main idea here
Note that the "add a close button in the annotation" is a part of what we aim in XWIKI-23740 .
This message was sent by Atlassian Jira (v9.3.0#930000-sha1:287aeb6)
If image attachments aren't displayed, see this article.