How can I make the corners of the modal form rounded?

The corners of the feathery popup modal are not rounded and I can’t seem to make them rounded.

Mind providing a link to the modal?

To repro:

  1. Sign up as a buyer
  2. Attempt to message a listing. A feathery modal will pop up with sharp corners.

The corners can be rounded by selecitng the overall step (outermost container) in the designer and setting the corner radiuses