My mobile phone has been working well before. Later, I saw a small fork in the cell phone signal, so I couldn't make a phone call or send a text message.

Enter CDMA subscription, switch between RUIM and NV, then fly mode, and then turn off fly mode.

If not, just

Modify/system/build.prop.

will

ril.subscription.types=RUIM

Replace this line with the following

ril.subscription.types=RUIM，NV

Then restart.

Re-enter the CDMA subscription, switch between RUIM and NV, then fly mode, and then turn off the flight mode.

If you can't solve it again, you can only brush back the official firmware.