I forgot that I used locals, which are a bit more difficult to debug.
There’s a line in the plugin that reads
x += dx, y += dy;
please insert console.log(x, dx, y, dy); directly above that so that it reads:
console.log(x, dx, y, dy);
x += dx, y += dy;
Press F12 and tell me what’s shown in the console there, if anything, when the cursor moves:
