Mmmmh. Hard to tell, unfortunately, without debugging. My guess is something along those lines. The common issues I usually face (or sometimes forget about) are:
- IPv6
- Implementing the transform pattern to remove unnecessary data
- Enough cycles for the calls
- Idempotency key
- Reproducible responses
- If none of the above work, using a proxy
Sorry, no other ideas right now, unfortunately. If something comes back to my mind, I’ll let know.