An Influencer's reach is a measure of the number of people who follow any given social media account. Tap gathers this data by making an API calls twice a month to the social media site requesting that data. Since we cannot grab the data in real time, sometimes there is a slight delay in any updates to the reach count.
Additionally, in order to make these requests, the Influencer has to give Tap permission to gather this data. This permission is stored in something called an OAuth Token. Occasionally this Token may become invalid or expired, and when this happens we are unable to update the reach count for that Influencer. In order to start being able to gather that reach data again, the Influencer will need to Re-Authenticate their social media account with the platform. Here is a link you may send to an Influencer to assist them with Re-authenticating their social media accounts.