The input signal to A and B pins at start up goes down to about -20V but ADM3065E seems to clamp it to about -11V as attachment.
1) Does ADM3065E has any clamp function inside?
2) If 1) is yes, the value of the negative clamping voltage is lower than -9V which is absolute maximum voltage of both A and B pins. It's still out of spec.
Should I take measures to fit the input signal to within the absolute maximum voltage (-9V~+14V), or I don't have to do any measure?
Yes the absolute maximum DC voltage on the A, B in put pins needs to be greater than -9V, and less than +14 V.
The DC voltage that you have on the bus pins is outside the maximum ratings for the device.
The answer to 1) is yes correct.
The answer to my question 1) is yes?