Wifi fails to connect after changing router (Libra 2) [SOLVED]

[Lukusaukko]

I'm leaving this here just in case someone else encounters the same issue:

BACKGROUND: I just changed my router and used the same SSID as the previous one. After that KOReader running on Kobo Libra 2 was unable to connect to the new network, and gave an error message about "Failed to connect to wpa_supplicant control socket".

SOLUTION: reboot your Libra/exit KOReader, change the wifi-settings in the stock software, and start KOReader again. Changing the wifi settings in just KOReader will not work.

EDIT: Later the reader dropped the wifi again. After some research, I realized it was most likely because the router was setup to use smart connections, that is a single SSID for both bands and leaving the router to sort out the connections. Libra 2 only supports the 2.4 GHz band and the router was not able to sort out the connection for some reason, so I set up a MAC filter on the 5GHz band to reject Libra's MAC and forcing the Libra to connect to the 2.4GHz band,which seems to work out (so far).