Changed router channel. Netwok key not agknowledged anymore while fine with mobile

[Lesko]

Hi,

I am currently accessing internet by WiFi, via my landlady's router and I don't have direct access to it.
My kubuntu laptop did connect until she changed the router channel this morning. I now keep on having the window to enter the network key (which didn't change), but when I click OK, it doesn't get aknowledged and fails to connect. While my phone running on Maemo connected straight away, like before.

My WiFi network adaptor is the RTL8723AE PCIe. It could connect before but not from very far, that's why the landlady changed the channel, in an attempt to generate a stronger signal.

Any idea why the network key doesn't get agknowledged anymore ?

Thanks in advance for any help.

[Lesko]

I have asked my landlady to change the channel again, and the network key was aknowledged on the other channels. So that resolved it. I can now access the internet.