Greasy Fork is available in English.
在Instagram页面加入下载按钮与开启按钮，透过这些按钮可以下载或开启大头贴与贴文、限时动态、Highlight中的照片或影片
I'm having the same issue. it doesn't work properly on Firefox. At least I still can download stories.
I have uploaded version 1.17.6. Please update and try again.
With Firefox, v1.17.5 doesn't work on posts, or front page (v1.17.3 still works, on posts only). Stories are working: the buttons are left of the screen under the IG username. Thank you for the quick updates! Respect!!