hi @westmaxx, Let's first connect the 2 Lopy4 in the same Mesh network.
What firmware are you using? what micropy scripts are you using? Could you run this tutorial: https://docs.pycom.io/tutorials/lora/lora-mesh/ ?
The LoRa 868 Mhz antenna is on the right side of the LED, as shown here: https://docs.pycom.io/gitbook/assets/lopy4-pinout.pdf
Also, please make sure you're using the same LoRa parameters on both boards? Band, frequency, bandwidth and spreading factor?