Same box but poor connectivity with RAK11310

Greetings
I built myself a box that I hid in the woods on a small hill some 1.5km from my home base. I started with a Heltec V3 but the battery drained to fast, which was expected I guess. I got good reception from my base and I could manage it over the mesh. Yesterday I replace the Heltec with a RAK11310, same antenna and everything and the node has dropped from the mesh. Signal strength is about the same as with the Heltec, around -100dbi, but traceroute works about 1/10 times and it rarely responds to mesh management. It does however send telemetry over the mesh which I don’t understand.
Is this expected behavior from a RAK11310 chip?

/Fredrik