Device: Keenetic Ultra (NC-1812), hw_version 1218C000
Firmware: KeeneticOS 5.01.B.1.0-0 (5.1 Beta 1, preview channel, built Apr 18 2026)
Chipset: MT7992-BE7200 (WiFi 7), SKU: #5.MT7992-BE7200-7975-7977
Resolved by: Downgrade to KeeneticOS 5.0 stable (main channel)
Problem
WiFi became completely unstable — both 2.4 GHz and 5 GHz bands affected simultaneously. Wired Ethernet worked perfectly throughout. The problem persisted across router reboots and WiFi radio restarts (interface WifiMaster0/1 down/up).
Symptoms
Wireless clients unable to auto-connect — must toggle WiFi off/on on the client device
When connected, connection drops after seconds to minutes
Drops are distance-dependent (worse at range) but also occur within 1 meter of the router
After drop, clients get stuck in "zombie state" — they think they're connected but the router has already deauthenticated them
Affects all client types: iPhones (iOS 18), iPads, Android (Galaxy S20 FE, Redmi A7 Pro), Huawei tablet, Denon AVR, Yandex Station, IoT sensors
~15 WiFi clients on the network
Log evidence (from self-test and syslog)
PTK 4-way handshake timeouts (router sends msg 1, client never responds):
May 8 11:26:31 WifiMaster1/AccessPoint0: STA(ba:c3:32:22:e6:9e) pairwise key handshaking timeout (msg 1 of 4-way)
May 10 19:36:31 WifiMaster0/AccessPoint0: STA(c4:82:e1:21:34:af) pairwise key handshaking timeout (msg 1 of 4-way)
MIC corruption during key exchange:
May 8 11:29:14 WifiMaster0/AccessPoint0: STA(1e:9f:6c:f6:d2:31) MIC differs in key handshaking
May 8 12:45:19 — same device, repeated
May 8 13:27:35 — same device, repeated
Group key handshake timeout:
May 9 12:00:14 WifiMaster1/AccessPoint0: STA(1e:9f:6c:f6:d2:31) group key handshaking timeout
RSN IE failure:
May 10 19:36:21 WifiMaster1/AccessPoint0: STA(1e:9f:6c:f6:d2:31) RSN IE sanity check failure (status code: 43)
Mass simultaneous disconnection — all clients on both bands at once:
May 10 19:42:57 WifiMaster0/AccessPoint0: STA(c4:82:e1:21:34:af) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster0/AccessPoint0: STA(00:06:78:4d:b7:9e) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster0/AccessPoint0: STA(82:a3:78:3d:23:24) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster0/AccessPoint0: STA(d4:12:43:ae:ef:62) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster1/AccessPoint0: STA(b2:92:d9:13:a9:53) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster1/AccessPoint0: STA(8c:c8:4b:a5:5f:db) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster1/AccessPoint0: STA(92:7a:20:d3:34:b1) disassociated by AP (reason: due to inactivity)
May 10 19:42:57 WifiMaster1/AccessPoint0: STA(82:fe:44:93:b9:91) disassociated by AP (reason: due to inactivity)
Constant "retransmits limit reached" for multiple devices across all 3 days.
What was ruled out
RF interference: Channel scan shows <10% load on both bands, minimal neighbor networks
Neighbor issues: Adjacent apartments report no WiFi problems
Channel selection: Tested manual channels (ch 11 on 2.4 GHz, ch 36/80 MHz on 5 GHz) — no improvement
Band steering: Disabled via CLI — no improvement
WPA3/FT: Disabled both — no improvement
Radio restart: interface WifiMaster0/1 down/up — no improvement
Router reboot: Full power cycle — no improvement
Hardware failure: No kernel panics, watchdog resets, thermal warnings, or PHY errors in logs
Configuration at time of issue
SSID: same on both bands (band-steering enabled)
Security: WPA2 + WPA3 (SAE), PMF, Fast Transition (802.11r)
2.4 GHz: auto channel, 20/40 MHz, BGN+AX+BE
5 GHz: auto channel, up to 160 MHz, AN+AC+AX+BE
WireGuard VPN active
USB storage (Seagate 2TB NTFS) attached
Resolution
Switching from preview channel (5.1 Beta 1) to main channel (5.0 stable) immediately resolved all WiFi issues. No configuration changes were needed — same settings work perfectly on 5.0.
Self-test diagnostic files from during the issue are available on request.