Device / setup
- RUT241, hwver 0005, firmware RUT2M_R_00.07.24.5. It was upgraded from 07.20.5 right after first setup; Wi-Fi was never tested on the old firmware.
- Mobile WAN via SIM1 (Swiss operator) works fine. SIM2 is the built-in bootstrap eSIM and is not used.
- For initial testing, LAN 192.168.1.99 is bridged into the existing home LAN, with DHCP on the RUT disabled.
- Wi-Fi settings: 2.4 GHz AP, WPA2-PSK (CCMP), country CH, HT20; 802.11r/k/v off, 802.11w off, “Disassociate on low ACK” off, client isolation off.
- Clients:
- whatwatt Go smart-meter reader (ESP32, 2.4 GHz b/g/n), powered via USB-C
- iPhone
Problem
Every client associates and completes the 4-way handshake, then leaves again 0.05–0.8 s later and retries about every 5 s, endlessly. No client gets a usable connection. Example from hostapd:
AP-STA-CONNECTED 1c:69:20:7b:f1:68 auth_alg=open rssi=-36
EAPOL-4WAY-HS-COMPLETED 1c:69:20:7b:f1:68
deauthentication: STA=1c:69:20:7b:f1:68 reason=8:DISASSOC_STA_HAS_LEFT rssi=-77
AP-STA-DISCONNECTED 1c:69:20:7b:f1:68
- whatwatt: 92 connect/disconnect cycles in 15 min; 54 of them were reason 8 (client-initiated), 12 were
4WAY_HANDSHAKE_TIMEOUT. - iPhone: the same loop, 131 times with reason 8.
- Earlier hostapd messages:
did not acknowledge authentication responseanddid not Ack EAPOL-Key frame. - RSSI at the AP is very strong (−33 to −45 dBm).
- MT76 reset counters are all 0, and the kernel log shows no Wi-Fi driver errors.
The pattern looks like the AP receives the clients fine, but the clients don’t reliably receive the AP’s frames.
What I tried
- The same whatwatt on a Cisco Meraki AP at the same location: stable, no issues.
- Forced CCMP, disabled “Disassociate on low ACK”, and checked that MAC filter and isolation are off.
- Deleted the SSID and created a new one: no change for either client.
i found some older threads too, but no Solution:
https://community.teltonika.lt/t/rut241-wifi-disappearing/16007/7