Check what channel your local area uses

Update: I bought another 433 MHz node and they work! Damn, this tech is so cool!

433 is not really popular here for the mesh networks. It's mostly dominated by weather stations, tire pressure sensors and gate remotes.

Over here meshtastic is pretty dead, just derelict repeaters. All the conversation is on meshcore so be sure to check there too

I know I'm late to the party, but did you ever find an answer for this question?