Hi Sadeep, On Thursday, 16 November 2023 at 16:56 (+0800), Sadeep Madurange wrote:
The AP is using frequency 5240MHz. This frequency is disabled on the T490 according to the output of iw list | grep -A 15 Frequencies:.
Great, so we know the problem! The ArchWiki page I linked earlier [1] has some advice on checking whether the firmware of your laptop is enforcing a hardcoded regulatory domain. This might be the case if the laptop's hardware was originally intended for another country.
I am in Singapore, and according to https://en.wikipedia.org/wiki/List_of_WLAN_channels, 5240MHz can be used here without restrictions. Additionally, I don't understand why this kicked in this week while working fine for about 2 months now.
Probably the access point changed its frequency. If you can configure the access point, you can set its channel to something supported. Jaron [1]: https://wiki.archlinux.org/title/Network_configuration/Wireless#Respecting_t...