Im on high sierra tho, could that be it?
Most likely not as I'm on high sierra and got it to work in chrome, but I had to explicitly allow that device. Honestly now I use this thread's method --> https://gbatemp.net/threads/tool-fusee-gelee-launcher-for-macos.502075/ along with the latest Hekate and it's working perfectly. Just be sure to make a folder named "payloads" (no quotes, lowercase!) and put the payload in there and it should work fine.