Are you sure that's the app you're using (that's the app key in your code, and you're using an access token for that app)? You do have a disabled app (but not the one with that app key), and it does show recent attempts to use it.
Something to double-check: make sure your code is actually using the access token you've generated and not an old token that's saved somewhere.
Just for future reference, the application started working a few hours later without any code changes. I am assuming that it takes some time for access tokens to be active. I am not sure exactly how much time this takes as I started working on the application again after a few days.
Access tokens do not take time to be active. They're active as soon as they're issued.
My best guess is that you were somehow still using an old token (from a disabled app).
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