You can’t connect to a Wi-Fi directly if it’s SSID has any non-ASCII characters on Raspbian in GUI mode. For example, if your Wi-Fi is called
素晴らしいチンチンもの, you can convert it to hex string with Python:
then copy this hex string to
/etc/wpa_supplicant/wpa_supplicant.conf without the quotation mark.
You can simply type the SSID to
/boot/wpa_supplicant.conf inside the quotation marks, it works. I have tried this before but didn’t notice it failed because the SD card was dead.