Device Xiaomi MI-2 Version : 3.1.25 Problem : Carrier not changing to HSDPA after update. Tried methods : testing simcard on other phone (Galaxy S3 [working fine, having HSDPA without any problem], HTC One X also no problem), Flashing older firmware (including stock jellybean) not changing back to HSDPA also, tried other carrier simcard also cant, flashing using fastboot with wipe all also couldnt solve the problem. Is there anyway for reporting this bug to Xiaomi? very frustrated after the update, and even now, not even downgrading firmware helps...might be related to kernel or radio firmware i guess...hopefully the HSDPA radio is functioning, if not I will send back to warranty EDIT : Tried adding a few commands for ro.ril in build.prop file... doesnt seem to work, suspecting the 3G chip is malfunctioning... Stress testing the 3g data, hopefully it'll get heat up and fix itself =( Day 2 : still on UMTS (3G), with no sign of improvement, bringing to warranty next week, guessed that Qualcomm WTR1605 has broken down for some reason.