That is correct. My friend’s mobile carrier said they would disable 3G in December. Not sure why she only experienced the issue this week.

The Poco F3 supports up to 5G. I confirmed that its 4G bands are compatible with the carrier. AFAIK, this phone model was not officially released in Australia so it’s probably not on the carrier’s list of 4G compatible devices.

After entering the code to disable carrier check, the VoLTE icon shows up on the status bar and calls are now working as expected.

Same. I have spare Google Rewards credits so I bought the in-app purchase to support the developer. Been using this app for probably over 10 years now.

One of my most frequently used features is the FTP file transfer to/from a Windows device or even another Android device.

eSim is a physical chip inside the phone.