OP wants to connect to some Wifi AP (a "router", some solar panel equipment, etc) which doesn't have Internet connection
using the web based Setup Wizard.
2nd step: he will choose that AP's network - set SSID, Security, Password and click Configure Wi-Fi.
Omega's response: Configuring ... and after a while ... Unable to connect to SSID Please try again
Meanwhile APCLI LINK UP, connection established, ifconfig OK, /etc/config/wireless OK although every Please try again attempt appends a record to the file.
It seems this config can be set manually by wifisetup or UCI or editing the /etc/config/wireless file - without problem.
I don't know - is this "reverse" config worse than the usual one (when that solar panel equipment's client connects to Omega's AP) or not?