If for whatever reason, someone you used to have a connection with decides to unfollow you, you need to do your end of the bargain.
You need to unfollow them back.
Just as when a friend asks you “how are you doing?” And you reciprocate that, when someone chooses to cut you out of their circle, you need to do the same.
People who take the effort to stay in your life are there for a reason.
Unfollow everyone else.