Difficulties with MR24D11C10 mmWave radar

Hi all.
I am trying to work with this module.
I have data coming from the serial port and the Arduino code from GitHub is delivering the data from the module.

A few problems:

  1. The module never seems to get back to an “unoccupied” state once it has detected a still or moving person.

  2. Has anybody deciphered the cryptic docs/case-statements about the different states and detection parameters?

  3. Has anybody got the S1 and S2 pins to operate? I am seeing only constant logic low on those.

Many thanks!