I just wanted to give a heads up to anyone else having issues with wifi not remembering your passwords. I was about to flash a different ROM because of this issue. I even tried the fixes mentioned earlier in the thread about editing your wpa_supplicant with no resolution.
I was flipping through my settings and also noticed that my modem was no OA8. I googled for the modem files and after flashing it as CP in Odin my wifi now remembers my password after a restart. I was getting very frustrated and hope this helps someone else out.