Default [Q] [Help] After Factory Reset to flash new ROM phone set for CDMA only?

I did a facotry reset (wipe all user data) thing to get ready to install a new rom on my N5. Flashing went great, but now once my phone boots it only has the option for CDMA in mobile networks and I can not edit it to do GSM for my AT&T APN's/SIM.

How can I fix it so that the Mobile Networks lets me edit it, or atlteast has a blank slate for GSM APN's?

Edit: Fixed (I think this is how), flashed a rom without gapps to get to the phone dialer, did the *#*#4636#*#* to get into the phone settings and changed it from LTE/GSM to CDMA ONLY then back to LTE/GSM and after a reboot, it seems the APN's are restored....Will try factory reset now and see if this sticks with the new ROM.

Edit: It's working! Hooray!