CHSEL0 and CHSEL2 in table 12 of the AD7616-P datasheet need to be be swapped.
AD7616-P
Production
The AD7616-P is a 16-bit, DAS that supports dual simultaneous sampling of 16 channels. The AD7616-P operates from a single 5 V supply and can accommodate...
Datasheet
AD7616-P on Analog.com
CHSEL0 and CHSEL2 in table 12 of the AD7616-P datasheet need to be be swapped.