ADS41B29: Analog Input Buffer at Very Low Input Frequencies

Tool/software:

Measured low frequency response:

For other ADCs (e.g. ads42xxx) there is Application Report SBAA220, describing similar behavior, originating from dual path of HF/LF amplification.

But for ADS41B29 there is nothing mentioned in the datasheet, and the parameters for compensation from SBAA220 do not fully match the observed distortion.

Is such a behavior inherent to the ADS41B29?