For some reason, I'm unable to access the API from a specific IP address. It seems to started when I migrated the app to a different server. Everything still works fine from the original server (and, indeed, from anywhere else I try it), so it isn't an issue with my credentials - the key works fine, and returns data as expected when run from anywhere other than where I'm currently trying to run it!
On the new server, though, it simply times out. It doesn't even give any kind of error message - it simply fails to connect at all.
I'm wondering, therefore, if there is maybe some firewall level blocking going on. I can't see any reason why my server would have been blocked for abusive behaviour (I'm careful to observe rate limits, and, as I said, the key still works fine from a different location), but it's possible that it may be collateral in blocking someone else. Or, maybe I've been unlucky and been assigned an IP address by my host that had previously been blocked for abusive behaviour!
Is there anyone on the network team who could investigate this? I'd be happy to take this off-forum, but for that I'd need some contact details.