In 2016, Instagram changed its algorithm to eliminate a feed full of chronological posts. Now, your post can only appear at the top of a user’s feed if it earns a certain level of engagement, signaling to Instagram that your post is popular and should be shown to more people.
Additionally, in order to rank highly, your post must receive engagement immediately. If your post receives likes and comments, but not within the first few hours after posting it, Instagram likely won’t boot it to the top.
The algorithm change is helpful for Instagram users — after all, I’d personally rather see posts most of my friends are commenting on and liking. However, it’s less useful for brands trying to spread their content to a wider audience. Plus, it can seem unfair.