I have made a SMA cable of length 1.952m after optimizing phase delay of LO. This is giving the maximum PDH error signal.
For future reference, I'm saving present setup details:
From the ratio of off-resonance value and error signal pk-pk at OUT1, we can check in future if everything is same as right now. From ratio of off-resonance value and dip value, we can check cavity mode matching in future.