RNode connection stability issues

My rnodes keep stopping working randomly: rnstatus shows rnode is still connected and shows the outdated info, but it doesn't update. I need to restart rnsd each time it happens. Though sometimes starts working without any intervention.

I have two distanced home servers connected via two rnodes over LoRa:

postmarketOS (rnsd 1.3.7) + Heltec v4 (rnode 1.86) via USB
OpenSUSE (rnsd 1.3.5) + Heltec v3 (rnode 1.86) via Wi-Fi

I encounter this issue on the both sides. At first, I thought the problem was with the Wi-Fi connection, but then I connected it via USB to one of the servers, and the problem persisted.

samsung-m0:~$ rnstatus

 Shared Instance[rns/default]
    Status    : Up
    Serving   : 1 program
    Rate      : 1.00 Gbps
    Traffic   : ↑12.94 KB   0 bps
                ↓417 B      0 bps

 AutoInterface[Default Interface]
    Status    : Up
    Mode      : Full
    Rate      : 10.00 Mbps
    Peers     : 1 reachable
    Traffic   : ↑5.47 KB    0 bps
                ↓8.49 KB    0 bps

 RNodeInterface[RNode LoRa Interface]
    Status    : Up
    Mode      : Full
    Rate      : 3.91 kbps
    Noise Fl. : -114 dBm
    Intrfrnc. : -85 dBm 19m and 5s ago    <- ??
    CPU temp  : 50°C
    Battery   : 100% (charged)
    Airtime   : 0.0% (15s), 0.34% (1h)
    Ch. Load  : 0.68% (15s), 2.91% (1h)
    Traffic   : ↑4.50 KB    0 bps
                ↓9.85 KB    0 bps

 Transport Instance <...> running
 Uptime is 47m and 41.85s

samsung-m0:~$

rns.recipes