当我取消关注instagram帐户时，为什么会出现错误？

Question

我在node js中使用instagram-private-api。当我关注200个用户并等待25分钟时，我开始取消关注这些用户，但是当用户数达到50个时，我就会出错

Unfollow user error IGAccountNotFoundError: Account you are searching 
for was not found!
 { [IGAccountNotFoundError: Account you are searching for was not 
  found!]
 name: 'IGAccountNotFoundError',
 message: 'Account you are searching for was not found!' }
 Unfollow user error IGAccountNotFoundError: Account you are searching 
 for was not found!

我同时使用单独的线程（child_process）用2个帐户登录。取消关注时我console.log（session）时，我发现取消关注时登录会话不存在。但是我不明白为什么？