RAK7268 looses 10/15 downlink messages

I am using a RAK7268, connected to AWS IoT Core, i receive all uplink messages as expected, but I am loosing downlink telegrams. I I issue 5 17-byte long downlink messages to 3 different Devices, I expect to get 15 Downlinks messages. This setup works well with other LoRaWAN gateways, but the WisGate IMHO drops messages:

Issuing the messages shows me 5 msgs in each device downlink queue in IoT Core:

…looks good. After a while, when the (ClassA) Device talk to the GW, they disappear. But in the WisGate LoRa Packet Logger I get:

only 5 msgs were sent to the devs - 2 msgs for 01A4B662, 1 msg for 01F26ß5A and 2 msgs for 005B23DB. 10 msgs are missing. From my device logging I see 5 instead of the 15 msgs.

from logging I get some:

Sat Jan 14 16:09:37 2023 user.warn basicstation[2164]: [S2E:WARN] ::0 diid=2628 [ant#0] - unable to place frame

plz help!

   Thomas

Good morning,

I dug deeper into this. If I send 100 messages ovver AWS IoTCore:

for i in {1..100}
do
  aws iotwireless send-data-to-wireless-device \
      --id MY_DEVICE_ID \
      --transmit-mode "1" \
      --payload-data "Eg==" \
      --wireless-metadata LoRaWAN={FPort=2}\
      --region="eu-west-1" \
      --output text \
      --no-cli-pager
done
echo "done"

and

grep unable /var/log/20230126072401.log 

on the WisGate, I get:

Thu Jan 26 07:39:33 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=38440 [ant#0] - unable to place frame
Thu Jan 26 07:39:48 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=21363 [ant#0] - unable to place frame
Thu Jan 26 07:40:01 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=4611 [ant#0] - unable to place frame
Thu Jan 26 07:40:13 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=30727 [ant#0] - unable to place frame
Thu Jan 26 07:40:33 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=29364 [ant#0] - unable to place frame
Thu Jan 26 07:40:36 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=27281 [ant#0] - unable to place frame
Thu Jan 26 07:40:39 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=2000 [ant#0] - unable to place frame
Thu Jan 26 07:40:44 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=44631 [ant#0] - unable to place frame
Thu Jan 26 07:40:51 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=13676 [ant#0] - unable to place frame
Thu Jan 26 07:41:05 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=53364 [ant#0] - unable to place frame
Thu Jan 26 07:41:19 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=35207 [ant#0] - unable to place frame
Thu Jan 26 07:41:23 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=6242 [ant#0] - unable to place frame
Thu Jan 26 07:41:30 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=41641 [ant#0] - unable to place frame
Thu Jan 26 07:41:44 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=18273 [ant#0] - unable to place frame
Thu Jan 26 07:41:58 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=7070 [ant#0] - unable to place frame
Thu Jan 26 07:42:10 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=46445 [ant#0] - unable to place frame
Thu Jan 26 07:42:21 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=11927 [ant#0] - unable to place frame
Thu Jan 26 07:43:26 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=38762 [ant#0] - unable to place frame
Thu Jan 26 07:43:38 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=60307 [ant#0] - unable to place frame
Thu Jan 26 07:43:48 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=19787 [ant#0] - unable to place frame
Thu Jan 26 07:44:26 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=18569 [ant#0] - unable to place frame
Thu Jan 26 07:44:34 2023 user.warn basicstation[13816]: [S2E:WARN] ::0 diid=7234 [ant#0] - unable to place frame

TTN Troubleshooting Gateways | The Things Stack for LoRaWAN tells in such a case

“If the gateway sends back a NACK, The Things Stack will retry sending in the next downlink window. This can also be caused by a hardware issue.”

but I do not see any retry… I tested out three different WisGates, so I do not believe it’s a hardware issue.

plz help

   Thomas