As already mentioned from @Zing check my thread if that helps:
I had the problem that WPA2 with SHA256 was enabled in my router menu / options in wireless security, however this does not work because of a bug in the current version 7.1.1. I tested various options and created an issue for resolving the bug for the project on gitlab, the issue has been found and will be fixed with the next release, check (recalbox developers on gitlab):
a. Check your router menu / wireless and security options
As workaround please set "WPA2 only" (e.g. with AES etc.) but without "SHA256" in your router menu.
b. Check your recalbox.conf file, if the following is set:
region is set to FR or JP? In my case, US worked as well
enable ertm = 1
Do you have any special chars in your PW? In the recalbox.conf it is mentioned that you need to escape these special chars, but it seems that this is not needed anymore.