My friend’s Poco F3 suddenly was not able to make or receive calls. Data and SMS still works. She has been using the same phone and Kogan sim card since June 2022.

We tried restarting, updating to the latest MIUI 14, testing the sim card in another phone (worked), and another sim card from a different carrier in the Poco F3 (worked).

In the end the solution that fixed it was to disable VoLTE carrier check by entering the codes below into the Phone Dialer. You will most likely have to toggle Airplane mode to reconnect to your mobile network.

Disable VoLTE carrier check * # * # 86583 # * # *

Disable VoWIFI carrier check * # * # 869434 # * # *

I wanted to share this tip as I have come across several posts reporting the same issue.

You should see a little pop-up notification to confirm that the carrier check has been disabled. Two additional toggles will also appear under Settings > Sim card & mobile network > Your Sim card settings

This website has a list of other Xiaomi devices compatible with these codes.