I may be having this same problem. GPT correctly formulates a POST request, claims it sends it, and then claims no response. (Not an unhappy code, no response at all.)
But I can’t find any evidence it actually sends it. I see no POST with Proxyman, and artificially sending one via Insomnia does get a response from the local server.
Additionally, the TODO example only sends POST requests, it never actually goes back and gets results with the built in GET.