"S" key does not work in X11 (XQuartz)
It appears that s has been mapped to Escape.

I don't know how it got be like this. I also don't know how to reset the map, given that setxkbmap -layout us (recommended by https://askubuntu.com/questions/29603/how-do-i-clear-xmodmap-settings) does not work. (It doesn't work for me either.)

So, as a last resort, if the only problem is s, then try

xmodmap -e "keycode   9 = s S ssharp Iacute"