Cellular data APN settings not working on Lumia 735 after W10M

[Windows Central Question]

Early May 2016 I installed the official W10M upgrade on my unlocked Lumia 735 in Australia. I have repeatedly entered APN settings from my sim provider but cannot get mobile data. The MMS settings work. The SIM settings screen/s in W10M allow me to enter a NEW apn but do not display current settings or saved profiles. Active Network name does not display (blank) on the SIM settings page and start screen. This is a single SIM phone. My SIM provider has asked that it be tested on another handset and the cellular data works fine. They correctly say that my problem is due to incorrect apn settings in my Lumia 735. The handset has been powered off/on, soft reset, hard reset, and is updated to 10586.318 with no resolution. Regards Jeff