After updating firmware to Vivo IQOO 13, the communication module firmware disappeared, and now the parameter is unknown! As a result, I cannot connect to any mobile operator, and for the same reason, the phone does not have an IMEI number. I contacted support and described the problem, and they advised me to bring the phone to a service center in China (which is a long way to travel from Ukraine). I asked them to provide the ability to unlock the bootloader on my phone, but customer support simply ignored my request. Now my new premium phone is just a gadget for accessing the internet. The Vivo IQOO user community has repeatedly requested the ability to unlock the bootloader, but all requests have been ignored. We will be responsible after unlocking, many need it to fix operating system errors, many block the bootloader again after fixing the errors. I strongly urge Vivo (BBK) to allow users to decide for themselves whether to unlock the bootloader or not, and for the company to provide this option.