When new topic/answer composer is open, if you click on “Insert date / time” and press Esc, it minimized the composer instead of closing the “Insert date / time” modal (a second press to Esc do close the modal)
It’s odd and unexpected (but not serious). As a side note, it works with the “upload” modal for example.
(Just in case it browser related: Firefox 73.0.1 64 bits on Windows 10)