If you download this post from a account's tagged channel,you will get a lower video quality than download it from the "reel" channel which is the example url.
Only happen on video post.
new finding:It turns out to be a mistake.the video of a post file will become bigger as time goes on
example post;https://www.instagram.com/reel/C_6-jyDI_4p/?igsh=MTQ5b3o0eG1rc3ZrNQ== tagged acount:https://www.instagram.com/chiara.asmr/tagged/
If you download this post from a account's tagged channel,you will get a lower video quality than download it from the "reel" channel which is the example url.
Only happen on video post.
new finding:It turns out to be a mistake.the video of a post file will become bigger as time goes on