Internal Comments posted with Ctrl+Enter discard the comment and silently close the form

On a ticket type we have, I am only able to create "Internal Comments", which are labeled with a red lock and "Your comment will only be visible to agents and collaborators":

On such comments,

• (works) If I submit them by clicking the "Add internal comment" button, the comment gets submitted as expected...
• (bug) ... but if I use Ctrl+Enter to submit the comment (similarly to many other forms in JIRA), the form disappears just as if it was captured properly, but the comment isn't submitted. I see that the button tooltip mentions Alt+S as the keyboard shortcut; ignoring Ctrl+Enter sounds legit then, but JIRA shouldn't glob my shortcut and discard my comment.