Tampermonkey Userscript (JS) Help!

Posted under General

I have some questions about scripting (Js) on the website, is anyone knowledgeable about that? Specifically Image Board Enhancer greasyfork userscript. I've made some modifications that seems to work almost perfectly in chrome, but when I switch to firefox, the addon doesnt work at all. My changes are here, i would love if someone who knows Js better could take a look at why it might work in Chrome but not Firefox. <3 thanks

Also, even though it works in chrome, i do have this tiny issue with one of the icons being way too small, which i have no idea why. https://github.com/vscum/Image-Board-Enhancer-Plus/blob/main/IBE%20Problem.PNG?raw=true