SM -N900L Cant switch LTE to 3g

[AC Question]

Hi,

I can't receive incoming calls because my phone is in LTE mode. Outcoming calls are fine. I don't know why its in LTE mode, as I don't believe this model supports it properly. I dont know how to switch modes as there are no Network settings option after accessing Mobile networks.

There is only an access point option which gives me no way to change modes.

What can I do here to switch modes?

 

[Nohone2]

I acquired it probably a year ago in Cambodia, so yes it is probably a knock off as almost all phones in Cambodia are.

Regardless though, this LTE mode never started popping up until about a month ago. I only just realized this LTE mode is preventing people from texting me or calling me.

I looked for a VoLTE app on my phone and all I found was the configuration menu, which I forced stopped.

I have downloaded Advanced Signal Status app, and when I clicked "Additional info", it's telling me my Device is locked.

What should I do?