This morning I put back the correct lockin parameters.

I started a measurement so that the polarization angle is close to 45 degrees.

This time, a new trouble with the HWP appeared : I can change the polarization angle (quite visible from the relative change of the p pol and s pol photodiodes) but the value on the angle value on the Kinesis software does not change.

I'll investigate this issue after all required measurements for this sample are finished.