By design, the Instagram API only allows us to retrieve posts from the past 24 hours. (see Facebook API page) Because of this, when you first add a new hashtag to watch, we can only retrieve results for the past 24 hours. Other networks, e.g. YouTube, Twitter, do not have this limitation.
Also, Synapview will also only retrieve a maximum of 50 new posts per hour for any one hashtag you have saved. If you are watching a hashtag that has more than 50 posts per hour, please contact us.