Thank you for the response. I am attaching the screenshot of the circuit I am trying to simulate. In the attached screen shot, I am introducing a current source at Q to maintain the required common mode output level. While debugging the circuit, I found that, the output is getting corrupted for different inputs each time I try to simulate and hence I am unable to create a test case where the output is getting corrupted.
Also, I noticed that common mode output gain of the circuit is greater than 1 for some common mode inputs. Would this result is corrupted output?
Any suggestions?