I doubt network is the real issue

10k rows is not a lot, even to transfer over the network as a single payload. So your problem is definitely not in the network, but somewhere in your code.

Must be something in your code that's creating latency, which is not obvious when run locally, but easily adds up over the network.

Lets say you are fetching 10k records, and some loop or something you're doing is introducing a network latency (e.g. server callback, logging, etc). An average of 1 extra ms for each row is 10,000ms which is 10 seconds.