I use a Jio SIM card and I don't get proper speed or signal. My friend sitting right beside me would use his mobile data from the same carrier but he would get nice speed. Even I put my sim card in his phone, it would properly, meaning that the problem is with the phone and not the carrier or sim. I put the same sim card in a Samsung A5 (2016), same condition, but when I put it in Samsung S8, it works superbly, better internet speed and higher signal strength. Can it be because of the system software updates?