Single message shown multiple times with different channels, SNR and RSSI in rxpk of IC880a gateway log

We have an IC880a SPI connected to an RPI3, antenna 8dBi. As a client we are using a Multi-Tech mDot.

During some tests we could not understand the following: we send one message (a confirmed uplink) but from time to time the gateway sees a single message multiple times:

{“rxpk”: [
{“tmst”:873783916, “time”:“2017-01-22T15:17:15.799187Z”, “chan”:2, “rfch”:1, “freq”:868.500000,
“stat”:1, “modu”:“LORA”, “datr”:“SF9BW125”, “codr”:“4/5”, “lsnr”:-9.5, “rssi”:-101, “size”:15, “data”:“gAOcIgcAKgABnIYky4ti”},
{“tmst”:873783916, “time”:“2017-01-22T15:17:15.799187Z”, "chan":6, “rfch”:0, “freq”:867.700000,
“stat”:1, “modu”:“LORA”, “datr”:“SF9BW125”, “codr”:“4/5”, “lsnr”:-6.5, “rssi”:-101, “size”:15, “data”:“gAOcIgcAKgABnIYky4ti”},
{“tmst”:873783924, “time”:“2017-01-22T15:17:15.799187Z”, "chan":0, “rfch”:1, “freq”:868.100000,
“stat”:1, “modu”:“LORA”, “datr”:“SF9BW125”, “codr”:“4/5”, “lsnr”:12.0, “rssi”:-45, “size”:15, “data”:“gAOcIgcAKgABnIYky4ti”}
]}

Some of them have a high RSSI value.

Used software:

*** Poly Packet Forwarder for Lora Gateway ***
Version: 2.1.0
*** Lora concentrator HAL library version info ***
Version: 3.1.0; Options: native;


Any ideas guys?

we have some suggestions about the possible problem
It seems we over heat contact antenna when doing soldering
and we are not correct to solder of antenna connector

on photo the connector is soldered incorrect

We did a hot fix (and moved the connector to the other side of the PCB).

After that all issues with the messages disappeared.

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