Care With Joy

Why does my signal indicator shift from 4G to H every time I make a phone call?

The signal is unstable. What should I do?

The call ends automatically when talking on my iQOO phone. What should I do?

What is VPN and what is the use of VPN?

Can I surf the Internet while I am talking on the phone?

Can I make phone calls without SIM card?

Why does my phone make phone calls automatically?

Can the MAC address be changed?

How to check the phone Mac address?

Why is my phone bill charged gratuitously?