Is there a request limit (not rate limit) for the API ?

[hobosapien]

I have a list of 15,000+ track names and I am attempting to retrieve trackids for each one through the Spotify API. I keep running into the same issue of the API freezing when it reaches a certain amount - in this case right around 2500 requests. I've tried 3 separate times thinking it was a rate limit, but I've kept them to 1:1s, 1:2 s, and now 1:3s which I thought was well under the API's rate limiter and they all fail around the same way - the API stops responding and I have to wait some time before trying again. This makes me think it is rate limited but I am not receiving a rate limiting error (no error in fact - it just stops).

What could be happening here? I am using the Authorization Code Flow and this is a Win 10 machine.

Thanks!