I recently bought a Raspberry Zero W and immediatly run into problem with the Wifi-connection. The problem was twofold, as is often the case with seemingly unsolvable problems. I spent the good part of an evening trying to work this ou. The root cause is that we are living in an apartement block with at least fifteen quite strong Wifi-routers around us and right across the street we have a hotel with a paywayll wifi. The Raspberry happily connected to the hotel and I mistakenly added it once, and that was enough to cause the first part of the headache. The next problem was that I routinely move our router to the least occupied frequency band, which happened to be channel 13. Maybe there were some additinoal interference not showing up in the Wifi-monitoring software I have, or the Raspberry Zero has a problem with higher channels. Anyway, the solution was twofold.
First, editing the Wifi config-file, removing the hotel Wifi that made the Raspberry to disconnect from our own router. Edit via e.g. 'sudo nano /etc/wpa_supplicant/wpa_supplicant.conf'
Secondly, moving our router down to channel 8 which is not ideal but good enough.
An additional update to the config file added a second Wifi in the form of a mobile phone hotspot and the resulting config file can be seen below. The Raspberry takes some time to switch between the two networks.
