Why the modification request is submitted without sources? [solved]

I edited a page of exonumia for adding the reverse/obverse engraver. When I  selected the reverse engraver using the keyboard and clicked “Enter”, the page was submitted without finalising the changes or adding sources.

I am a referee for that page. Could this be the reason? If so, I think referees should also write sources.But… as referee I saw other requests without sources.

You answered your own question! 

When making small edits to a page it's a pain to have to write sources all the time. 

Ok, then I assume normal users need add sources, and referees do not. I transform this topic in a question solved.

I published a suggestion: to submit the page only when the button is clicked.