PrismKDog, Feb 17, 2017 : Recently installed OxygenOS 4.0.3 update, since then cellular data drops. A small exclamation mark appears on the cellular icon on the status bar if Android. When turning cellular data off for a while and back on it finally connects. Sometimes after the data connection has been established for some time, again the little exclamation mark appears and no data connection exists. Please look into this!