Public bug reported:
## Problem description
The Intel Wireless-AC 8265 in this ThinkPad T480 disconnects from the access
point
several times per hour while the signal is strong (-58 dBm, beacon signal avg
-50 dBm).
Each disconnect is preceded by a flood of:
```
iwlwifi 0000:03:00.0: missed beacons exceeds threshold, but receiving data.
Stay connected, Expect bugs.
iwlwifi 0000:03:00.0: missed_beacons:19, missed_beacons_since_rx:1
```
The driver keeps the connection up because data still flows, but the AP
association is
eventually dropped and re-established:
```
wlp3s0: Connection to AP dc:f8:b9:ad:f0:cf lost
wlp3s0: authenticate with dc:f8:b9:ad:f0:cf (local address=...)
wlp3s0: associated
```
In one 13-minute window there were **6 disconnects** and **571 missed-beacon
messages**.
In an earlier session the counter reached **3438 messages** in one boot.
## Environment
```
Ubuntu 26.04.1 LTS (Resolute Raccoon), kernel 7.0.0-38-generic
Lenovo ThinkPad T480 (20L5)
03:00.0 Network controller [0280]: Intel Corporation Wireless 8265 / 8275
[8086:24fd] (rev 78)
Subsystem: Intel Corporation Dual Band Wireless-AC 8265 [Windstorm
Peak] [8086:0010]
Kernel driver in use: iwlwifi
Firmware: 36.c8e8e144.0 8265-36.ucode op_mode iwlmvm
```
Connection details at the time of the failures:
```
channel 10 (2457 MHz), width 20 MHz
signal: -58 dBm (beacon signal avg: -50 dBm)
rx bitrate: 130.0 MBit/s MCS 15 tx bitrate: 117.0 MBit/s MCS 14
beacon interval: 100 ms, dtim period: 1
tx failed: 9, beacon loss: 0
```
## Already excluded
- `power_save = N` (power saving is already disabled)
- `bt_coex_active = Y`
- Signal strength is good; the AP is ~2 m away with no wall in between
- The problem exists on both 7.0.0-38 and 7.0.0-42 — it is **not** a 7.0.0-42
regression
- `iw ... station dump` reports `beacon loss: 0`, i.e. mac80211 itself does not
count
lost beacons, while iwlwifi's own counter overflows constantly
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
--
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https://bugs.launchpad.net/bugs/2172528
Title:
iwlwifi 8265: frequent disconnects and "missed beacons exceeds
threshold" on 2.4 GHz (Ubuntu 26.04)
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