RAK2287 latest Firmware issue w Joins and Data

Issue: with rPi+RAK2287, chirpstack firmware V4.2.7 has issues with joining and working with devices from Heltec (CubeCell) and Dragion (LDS01) that join and work fine with V4.2.5 firmware

Setup: US915, built-in application “service-profile-build-in”, device profile “device_profile_otaa”

Server: rPi+RAK2287

Details: Following RAK2287 quick start guide setup of rPi. previous setup works fine with V4.2.5, but newly assembled LoRaWan gateway with RAK2287 does not join devices well. When channel mask allows joining, no device data LoRaWan frames.

You’re going to need to be more specific.

Channel masks have nothing to do with allowing joining, other than that as for all traffic they have to match what the node is transmitting on.

Actually, the LoRaWAN spec says that nodes should try joining on all legal channels, because they don’t know anything about the channel mask of the network they are joining. Though many nodes cheat relative to the spec and only attempt joins on the channel mask used by the network they want to join, as this is more efficient.

If you have one setup that works, and one that does not, a key step would be to compare the system logs of each, particularly the messages during the startup of the packet forwarder, and if that keeps running or errors out.

Also make sure the public/private preamble setting is correct, if that mismatches only around 1 packet out of 10 will leak through.

@cstratton Thanks for the reply. I am unaware of a Publi/privat preamble, so will investigate per your comment. Thx!

@cstratton, Chris, kindly point me to where I set the “public/private preamble setting”. I’ve been thru a fresh ChirpStack install again on my rPi4/RAK2287 gateway with the same issue of successful otaa joins from a Heltec CubeCell AB02 node with the boards example code (LoRaWan_OLED), but onl;y about 1 in ~40 subsequent data transmissions are showing up (not even as LoRaWan frames in the Gateway (10 feet away) that the AB02 received the accepted join from). I see that a different rPi4/RAK2287 gateway (50 feet away) sees the LoRaWAN frames sent by the Heltec CubeCell AB02 node. I’m still thinking the issue is with the ChirpStack Gateway configuration rather than the Heltec CubeCell AB02 node LoRaWan settings??
Your guidance is appreciated! Here is the initialization I last tried with the Heltec CubeCell AB02 node :

AT Rev 1.3
+AutoLPM=1

+LORAWAN=1

+KeepNet=0
+OTAA=1
+Class=A
+ADR=0
+IsTxConfirmed=1
+AppPort=2
+DutyCycle=15000
+ConfirmedNbTrials=4
+ChMask=00000000000000000000FF00
+DevEui=631564974E______(For OTAA Mode)
+AppEui=0000000000000000(For OTAA Mode)
+AppKey=4152878AE4EFF37849D455184422CC59(For OTAA Mode)

LoRaWAN US915 Class A start!

joining…TX on freq 905100000 Hz at DR 3 power 20 dBm
TX on freq 905100000 Hz at DR 3 power 20 dBm
RX on freq 926900000 Hz at DR 13
RX on freq 923300000 Hz at DR 8
TX on freq 904900000 Hz at DR 0 power 20 dBm
TX on freq 904900000 Hz at DR 0 power 20 dBm