Default ViperXL Rom 4.2.0 APN problem

Hello. I have a little problem. After i installed the new rom Wiped everything . The rom started fine. everything is smooth. only problem was I can not save my APN setting for mobile data. I input everything then click save but it just exit out and have no record of the new APN i just added. Is there a fix for it so i can turn on my mobile data and use it?. right now i can only use WiFI

Best regard John