Facebook throwing strange error when attempting to create custom audience with sandbox ad account

Question

My team has had a FB marketing/business account for 2 years now, and we opened our sandbox account around that time. However, when I run my script to create an audience for the sandbox account, I receive this error:

status: 400,
  response: {
    error: {
      message: '(#2654) Customer List Audiences Are Not Available: Ad accounts owned by businesses new to Facebook Products can create customer file Custom Audiences after several weeks of following our policies.',
      type: 'OAuthException',
      code: 2654,
      error_subcode: 1870054,
      fbtrace_id: '*****'
    }
  },

I've accepted the ToS as many answers have previously suggested. I've been able to populate the sandbox with other data, but creating an audience is giving me serious problems. If anyone has run into this issue or has any suggestions, I'd really appreciate the feedback.