Mobile Network Keeps on Switching and other problems
Hello !

I have a problem with my joying.

My simcard is well recognized but keeps on switching network.
With some reasons when i'm in 4G, some apps will not work but they work with a lower network, like edge or else. They act like there is no mobile network at all when the system hits 4G.
Some apps (youtube, maps and maybe others) works fine in 4G.

I tried lots of manipulation and reboot but nothing change.

Do you have some suggestions?