With firmware 2.0.13 (set to EU_868, LONG_SLOW, no other changes after factory reset), I get this:
rx_snr: 6.75 dB / rx_rssi: -53 dBm
rx_snr: 5.25 dB / rx_rssi: -53 dBm
rx_snr: 6.75 dB / rx_rssi: -49 dBm
rx_snr: 7.25 dB / rx_rssi: -40 dBm
rx_snr: 6.0 dB / rx_rssi: -37 dBm
rx_snr: 5.5 dB / rx_rssi: -38 dBm
rx_snr: 4.75 dB / rx_rssi: -38 dBm
…
(some random samples, checked in Android app, after enabling debug logs)
To switch back to version 2.0.13 (discussed there: Remote Node Administration does not work, somehow - #27 by SR7673 ) didn’t solve the issue in my case yet, but the SNR/RSSI values seem to have improved a bit.