ADXL355 FIFO behaviour, fill and read


I am using the SPI interface and I am reading the complete FIFO (96*3=288 bytes) from the ADXL355 by blocks of 9 bytes in the MCU. After a complete loop, I check the FIFO ENTRIES and I see it is very close to 0 (or far from 96).

1) Does it means that after every read the FIFO get empty and it takes some time to fill up again? I read that the FIFO operates in "stream mode" and new data overwrites the oldest.

2) Is this time related to the delay in the filter settings?

For example I am using a LPF with ODR 4Hz and corner 2Hz which will give a delay of 190ms according to the data sheet.

2.a) Does it means that every 190ms the FIFO will fill a reading for X,Y and Z (i.e. a 9 bytes block)?

Thank you for your help,