That is interesting, perhaps roblox somehow implemented ping wrong. But by definition, ping is a round trip, so if this was single trip calling it GetNetworkPing seems a little misleading. Regardless I’m not sure if the method is even completely implemented yet. Once it goes live more info will probably be available.
The FFlag for adding it changed, so the release note never updated. I believe they re-implemented it, and placed it on another flag. The official release was never announced, and it was broken for some time because nobody was made aware it went public.
I kept testing and it always returned zero for like a month, and it turns out the FFlag changed and it was actually broken the entire time