Why Medium ate the Polish Ś, and a Cold War keyboard hack is to blame (aresluna.org)
On Medium, Ś vanished while the eight other Polish accented letters typed fine. Marcin Wichary traced it: the Polish 'programmer's layout' makes Ś with Right Alt+S, Windows remaps Right Alt to Ctrl+Alt, and Medium's save handler was swallowing anything with Ctrl+S to block the browser save dialog.
The one-character fix: stop firing on Ctrl+S when Alt is also held. The flip in the thread is that browsers still give developers no clean way to tell these key combos apart, so the bug keeps coming back.