RAK5146L 433MHz concentrator issue : bad RX level ....negative SNR with short range

Issue: Very bad RX level with RA5146L 433Mhz gateway
Setup:RAK5146L connected via SPI on a linux board with Packet forwarder
Used this code : GitHub - RAKWireless/rak_common_for_gateway
I followed this tutorial to install firmware :
Quick Start Guide for Raspberry Pi and RAK LPWAN Concentrators | RAKwireless Documentation Center
Used this global_conf.json : lora/rak5146/global_conf_uart/global_conf.eu_433.json
I also use the same RAK5146 module in EU868 version and it work fine.

What am I doing wrong ?
I have a doubt about the concentrator reference (see sticker bellow) ?
I purchased a RAK5146 module with the SKU:511014


I found this information on rakwireless documentation :

So 415 is a 433M gateway