Atheros wifi adapter keeps dropping in 26.04

[zpiatek]

I'm sharing an issue I submitted at https://bugs.launchpad.net/ubuntu/+bug/2154089.

Hello, I need to report a bug in K/Ubuntu 26.04 running on a Dell Inspiron 2350.

This PC runs fine with K/Ubuntu 25.10 and previous versions, but when I try 26.04, the wifi adapter will drop after a few second, then connect again. The cycle repeats.
A popup on the screen reads:

Network Management
Wireless Interface (wlp4so)
Authorization supplicant timed out.

I tried to file an apport when I ran ubuntu-bug but the connection problem won't allow it.

The wifi adapter is a Qualcomm Atheros QCA 95565/AR9565 wireless adapter. The kernel driver is ath9k.

I tried running a few commands when I researched the problem in https://launchpad.net/ubuntu, but didn't see one posted for 26.04.

Again, this runs fine on Kubuntu 25.10 and previous. Could this be a Linux 7 issue?

Any help would be greatly appreciated, and thank you in advance!

[Snowhog]

AI Overview

The "Authorization supplicant timed out" error on Kubuntu 26.04 (wlp4s0) usually indicates a failure between NetworkManager and the Wi-Fi driver to complete the WPA handshake, often caused by power management, driver incompatibility, or crowded channels. Key fixes include disabling Wi-Fi power saving, updating firmware, or switching from wpa_supplicant to iwd.

Immediate Fixes

• Disable Wi-Fi Power Saving: Create/edit /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf and set wifi.powersave = 2 instead of 3.
• Restart NetworkManager: Run sudo systemctl restart NetworkManager.
• Forget and Re-add Network: Delete the network profile in KDE Plasma settings and reconnect to refresh security credentials.

Advanced Troubleshooting

• Switch to iwd Backend: If using wpa_supplicant, try switching to iwd for better stability on newer kernels.
• Check Kernel/Firmware: Ensure you are on the latest kernel, as chipset support (especially MediaTek) changes frequently.
• Disable 802.11k/v/r: If using a high-end router, disable fast roaming (802.11r) or BSS transition management (802.11v) as these can cause premature disconnections.
• Access Point Settings: Ensure your router is not forcing 5G or 6G channels that the card handles poorly, and ensure the router channel is not highly congested.

If you are using a MediaTek card, you may need to look into updating firmware-sof-signed or installing specialized firmware packages, as they are often prone to this specific error.

[zpiatek]

I have disabled Wi-Fi Power Saving by setting the value to 2. I then restarted the NetworkManager. I also deleted the network profile and then added it back in.
No change.

[zpiatek]

I then ran the following commands to switch from wpa_supplicant to iwd (which only made the matter worse where the wifi connection doesn't work at all):

In /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf, I changed wifi.powersave = 3 to 2. Saved it and ran "sudo systemctl restart NetworkManager" to restart it.

I then changed wpa_supplicant, to iwd. I ran the commands:
sudo apt update
sudo apt install iwd

I updated /etc/NetworkManager/NetworkManager.conf by adding the line:
wifi.backend=iwd

I started iwd with the command:
sudo systemctl enable --now iwd

I ran these commands:
sudo systemctl stop wpa_supplicant
sudo systemctl disable wpa_supplicant
sudo systemctl mask wpa_supplicant

sudo systemctl restart NetworkManager


Lastly, I ran sudo systemctl status iwd

Here is a dump from the command:

kubuntu@kubuntu:/etc/NetworkManager$ sudo systemctl status iwd
● iwd.service - Wireless service
Loaded: loaded (/usr/lib/systemd/system/iwd.service; enabled; preset: enabled)
Active: active (running) since Mon 2026-05-25 18:08:50 UTC; 2min 21s ago
Invocation: 8a9957a12b104d538a3bf157eaa27f87
Docs: man:iwd(8)
man:iwd.config(5)
man:iwd.network(5)
man:iwd.ap(5)
Main PID: 10070 (iwd)
Tasks: 1 (limit: 12269)
Memory: 804K (peak: 2.1M)
CPU: 205ms
CGroup: /system.slice/iwd.service
└─10070 /usr/libexec/iwd

May 25 18:08:50 kubuntu iwd[10070]: udev interface=wlan0 ifindex=4
May 25 18:09:07 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:09:07 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:09:07 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:09:36 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:10:11 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:10:11 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:10:11 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:10:41 kubuntu iwd[10070]: Unexpected connection related event -- is another supplicant running?
May 25 18:10:47 kubuntu iwd[10070]: event: state, old: disconnected, new: autoconnect_quick
kubuntu@kubuntu:/etc/NetworkManager$