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在Instagram頁面加入下載按鈕與開啟按鈕，透過這些按鈕可以下載或開啟大頭貼與貼文、限時動態、Highlight中的照片或影片
I use Firefox (Windows10) and have download buttons on both stories and posts, albeit not on saved post, but I don't think that was supposed to be addressed in this update.
From what I have observed: On some 'saved' posts, you will get the option to download them. The difference seems to be if the profile is public or private. It looks like instagram recently changed behavior and is removing the 'share' arrow button on accounts that are private. Unfortunately, the script is using the existence of this button to add-on the download buttons and since it may not exist, it breaks the script.
You can fix this on Firefox by going to "about:config" in a new tab and setting "layout.css.has-selector.enabled" to true because this is ultimately an issue with the has: css selector
Something that i noticed is that on chrome sometimes the button is not where it should be and then it breaks the layout of the stories. Like on that screenshot. Had to "censor" the screenshot cuz of the size limit of screenshots here, sorry.
From 1.17.6, the has selector has been removed. Please update and try again, if you are using Firefox.
About the layout, I will investigate this issue.
no download button on firefox even with the last update