Negatie SNR with UfiSpace gateway

Negatie SNR with UfiSpace gateway

I have problem with data lost in communication with UfiSpace gateway. The download data lost is sometime about 20%.
The download massages parameters on end device are SNR: -9 dB and RSSI: -71 dBm. I have read the SNR should be positive to sucessfull encoding. The distance between end device and gateway is 1 meter.

If I use different gateway with different LoRa provider the values are better (SNR: 11dB, RSSI: -24dBm) and data lost is below 2%.
Is there possibility to increase radio TX power from UfiSpace gateway? I guess the signal is too weak.

The end device is ST Nucleo Board with semtech LoRa library.

Thanks for any ideas.