Is my device compatible with 4G VoLTE and can it function after 3G network shutdown?

[canyon_flower]

Model Name: ASUS_X00TD
Firmware Version: Android 8.1.0
Serial number: JAAAGF03U998LHL
Frequency of Occurrence: Currently not able to connect to phone carrier service
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
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My phone carrier (PureTalk USA) shut down its 3G network. My device stopped connecting to service (I am not able to call or text over SMS). I thought my device supports 4G VoLTE, so I don't understand why it can't connect. Will changing my SIM card solve the problem? Or does my device not actually support 4G VoLTE?
I have tried switching my SIM card to the other slot, that didn't work. I have tried restarting my phone, and also updating the system software to the latest version offered.

[fussion_ASUS]

Hi, we request you to provide us your device's latest firmware version. You can follow the below instructions to do the same: Settings -- About -- Software Information.

[ASUS_Bot]

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