I read correctly (CRC correct) the digits SNA_3 to SNA_0 and SNB3, but SNB_2 to SNB_0 return to 0xFF with CRC faulty.
I have the same problem with Si7021 on Happy Gecko board.
Is there any hiden trick ?
0xFF is normal for the other bytes. the CRC should be correct, but you do not need to worry about that.