because of broken javascript (in pm27's view):
23:49:37.582 SyntaxError: invalid for/in left-hand side 1 app.js:1:234335
and that `for` block looks like this:
for(const i of e.split("&")){let[e,a]=i.replace(/\+/g," ").split("=");a=void 0===a?null:o(a,t),n(o(e,t),a,r)}
in MDN, it stated that fx < 51 using `for...of` with `const` keyword will cause syntax error.
if you have link to userstyles.org, let it load and view source. find "stylish-code" line, click on the css link, copy all and then paste it on new style.