I would definitely recommend to use any of the LoRaWAN examples for a V3 board, as the V2s have an other chip which is partly incompatible. So that’s a no-go.
I have zero experience with Helium, but there are at the bare minimum a couple things to pay attention to:
- frequency (not the default 868 that is configured)
- how you generate the devEui (default is generated by ESP’s chipID, but you should set to Custom if generated by Helium)
Note that I am unsure if Helium gateway locations are always correct - at least on TTN, some users purposely set a similar but incorrect location to hide their address or gateway location. So it may not actually be the case that you are exactly at the correct location. And maybe that person deployed it within a house or basement for personal testing, which may limit coverage as well.