Comment by eitau_1

Sad reality of replacing plain old text boxes with "smarter" re-implementations: https://utcc.utoronto.ca/~cks/space/blog/web/WebEditingVsCut...

Some (including the most popular: codemirror) go as far as putting themselves inside "natural" selection flow: they're interpreting mouse inputs, cancelling default behavior and selecting text themselves (programmatically via setSelectionRange). And Firefox deliberately ignores such selection: https://searchfox.org/firefox-main/rev/edb7c6118aa4fc5b09d84...