@webodan Do u use hidden SSID?
Same problem here while that Raspbian support all wifi channel.
For me, on the last channel supported (ch 6) = bandwidth / 2 
Version 4.1 correct/will correct this problem ?
@Pepe No. Still no wifi on the Pi whatsoever. The only thing I could try is reinstall Recalbox all over again but it will be a major pain to manually copy over everything I had. Still the same Recalbox 4.0.0, wifi in channel 11, 2.4ghz, rechecked that the password and the SSID were properly inputted and (just in case) that I didn't have anything blocking the SSID in the router's settings. Everything is fine and dandy and even my s**tty conceptronic USB wifi dongle I use in a livingroom PC works perfectly. I tested every single device I had lying in my home that could run on WiFi and I have no problems at all. Just the d**n Recalbox won't connect. Something indeed went horribly wrong on the wifi support since I can't even go back to my previous settings without some hours of reinstalling chores in the middle. @Substring
@webodan Using channel below 12, i think u could try this:
https://github.com/recalbox/recalbox-os/wiki/Manual-IP-settings-(EN)
@Pepe in those commands should i use eth0 or wlan0?
@webodan Eth0 for wired connection, wlan0 for wifi.
@Pepe Thank you for your help.
I followed the settings explained, but I only edited wlan0 with a static ip (as i don't plan to use ethernet). Same wifi configuration error.
If i can't get any more help I'm gonna try restoring a backup, as I have an img file of the SD card before it somehow crapped out just by changing the wifi channel and changing it back.
In recalbox.log all I see is that it starts wifi and then wifi times out.
@Pepe if ti doesn't connect, setting a fixed IP won't help 
the thing is that i don't remember at all the manual commands to test wifi ... wpa-supplicant is not really "user friendly"
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@Substring I have recommended following the manual ip management instructions since in version 4.0 with the previous connection manager there is a dhcp management problem in wifi in certain cases / configurations, which at its time I could solve in my case by setting ip fixed. The symptom was the same as mentioned here, does not connect via wifi. There are many causes that can give that result and this is one of them. It is not very clear what happens to the user, at least to me is not clear with what he is commenting and trying things always provides information. I keep in mind what happened and I will not recommend further tests to users, the intention was to help not to disturb. Sorry for the inconvenience.
@Pepe it's worth trying your solution anyway 
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@Substring okie dokie, ten four, copied, message received 
I restored a backup and the wifi came back, it had the same settings as my previously faulty install had. Weird.
@Pepe Thank you for your help.
I followed the settings explained, but I only edited wlan0 with a static ip (as i don't plan to use ethernet). Same wifi configuration error.
If i can't get any more help I'm gonna try restoring a backup, as I have an img file of the SD card before it somehow crapped out just by changing the wifi channel and changing it back.
In recalbox.log all I see is that it starts wifi and then wifi times out.
