I have nothing 3a phone. I use Bsnl 4G sim in this phone I recently seen that this phone is only supporting 2100mhz band in BSNL 4g but 700mhz (B28/28) band not working . In the same time and same location my another phone BSNL 4g 700mhz band support. I have also verified this in nothing official website there write that in phone specifications 4g 700mhz (B28/28) band support in this phone but practically not supporting right now I think this is need a software update fr unlock the band .so please fix this problem as soon as possible