WiFi connections from my laptop became unstable after I upgraded it to Ubuntu 19.04. To get them to work, I had to turn the WiFi adapter on and off several times, which quickly became annoying.
The following attempts to fix the problem were unsuccessful:
- disabling IPv6
- disabling power-saving on the WiFi adapter
bt_coex_active=0during kernel loading to disable Bluetooth/WiFi interference protection
Eventually the correct solution was to disable 802.11n with the following procedure:
- Edit or create a configuration file under
- Add this line and save the file.
options iwlwifi 11n_disable=1
- Reload the iwlwifi module.
sudo rmmod iwldvm
sudo rmmod iwlwifi
sudo modprobe iwlwifi
- Connect to the WiFi network.