when you edit part of a phrase in a text input, then hit the Enter/return button, often ff
replaces your typing with an earlier-submitted phrase.

2 cases:
1) likely the Enter key did *not* activate the submit button. Only your carefully editing
was (annoyingly) wiped out by hyperactive history. to fix that, you can context click in
text, choose Undo from menu.

2) assuming the submit button *was* activated, you will first have to use browser
Back (arrow button) before doing the same context click, Undo.