Hi @User22824 ,
There are two bits in the MOD1 register (IICadr), which define the slave address. So, even if it is an A1 sensor chip, but we accidentally wrote 00 instead of 01 (00 for A0 and 01 for A1), the A1 sensor chip will act like an A0 sensor chip.
I went through your code and saw that the IICadr value is correctly defined as 1, which is for the A1 sensor. So, could you please confirm IICadr value was 1 when you observed this issue?