Phones from Android One program will regularly receive updates to the newest versions of Android system. Xiaomi's first phone from this program, Xiaomi Mi A1 received update to Android Oreo on 31st of December, but then people noticed some problems with how phone works on the new version of Android.
Some people noticed that phone restarts without any reason. Sometimes phone freezes during using standard apps like camera or dialer and they don't respond. It's worth mentioning that it's nearly impossible to use Bluetooth connection for a long time because this option drains battery after several minutes. That's why update was suspended at this moment and you can't download it from the Internet for your phone. When all bugs will be repaired, then Xiaomi will upload repaired version of system on their servers.