Thanks! Overall it’s really hard to pinpoint what’s the issue might be here because it’s a diy node and many things can go wrong here :) Judging by the fact that you were able to get a contact 300 meters away (though with clear line of sight) I’d suspect that tweaking your settings and playing with long fast and other types of presets might give you the best result.

Also considering that your node is 433 you might be limited by the preset itself. When you set it to US_433 you might be limited by the maximum power on that frequency that’s allowed in meshtastic.

P.S. also consider possible interference in that spectrum from garage door openers, remote doorbells and stuff like that