Sorry everyone - turns out an assortment of code bugs, network issues (openai going down, and my home internet also going down…), and token limits conspired to confuse me. After re-running everything a few more times, all the “small” requests did finally resolve.
And, it turns out that all the “large” ones are not working because a bug in my code let some slip through with more than 8191 tokens inside. Oops!
Thanks for the help and suggestions still!