Reply / Private Note button formatting lost

In a new deployment of Help Desk the New Reply and Private Comment buttons on the tickets form have lost their formatting. They now display as simple text links. I have verified that the CSS for the form is the same in other deployments.

Hello! Do you mean that they look like below?

If so, it is by design: in the latest version of the ticket forms we changed the layout to a lighter view. You can switch to the rich text editor in the HelpDesk appearance settings and it will bring the buttons back.

That change works. As a comment, the "cancel" link is removed in the "Light" version and restored with the "Rich" option.