iOS Instagram has gotten increasingly useless. First they take previews out of post notifications; now, whenever you open one notification, all the other Instagram notifications disappear. So post notifications are no longer actually useful. Yet they're necessary because of the idiotic algorithm (probably designed to reduce server load and not to "optimise experience") that no longer displays a chronological feed, but "prioritises" certain posts and skips a lot of posts it considers less useful.
Morons.