User not registered in Developer Dashboard

[krh1502]

I am having an issue with a small personal project I am working on. It was working perfectly for many users until one person I registered today. I make 3 requests to the Spotify API after getting an implicit grant from a user who I registered in my app's settings dashboard. All 3 requests in succession were working. Now, I have to remove and re-add the user to my developer dashboard before each API call. Not sure why this is happening. The error is 403 Forbidden and the body returns: User not registered in the Developer Dashboard.