19s ROM
1. Modems bands are correlated with ROM. (X520,X526 China - no B20, X522 USA - no B3, B20, B38, x526 Global - OK, X527 no B38 TDD. In my opinion x526 19s, 21's ROM (India) are OK. Modem work in B1, B3, B7, B20 and B38 bands (these 4G bands are used in my country).
2. Over 19s ROM I...