The problem is resolved. The value of increment in frequency was too small compared to the frequency resolution of the generator ... when I set it to 50mHz, all is ok ...

Hello, I have a problem with the generator of my pico 5444B. The frequency setpoint does not seem to be respected. The signal from the AWG passes through a 2nd order low pass filter with 0.35Hz cutoff frequency. I do not understand why all frequency deviations are not equal to about 30mHz as expecte...