Downloading is possible for both photos and videos from posts, as well as for stories, reels or profile picture.
When this problem occurs to you, please use F12 to open DevTools and switch to the CONSOLE tab. Screenshot all the messages in it (or only the ERROR part) to me to confirm the problem.
Because this didn't happen when I tested it so far.
Before that, you can try reinstalling the script first.
The above problem disappeared for me.
However, another problem appeared, the stories stopped working today, probably Instagram changed the post id or media id.. In the F12 console, no error appears, only "isStory"
There was no problem when testing it on my two accounts here. Therefore, it may be that Instagram recently updated and tested the new layout. Please open a new issue on Github, and press the ALT+Z hotkey on the story page to paste the DOM tree in the input box into the Github issue.
https://github.com/SN-Koarashi/ig-helper/
I don't know if the problem is on my side but the menu settings don't work, I change them but they don't save, they always go back to the default settings if I refresh the page, I have to manually change lines 42 to 46 to save.