i forgot to post it here
i showed it to a mechanic, the issue was gone when i went there so they said nothing is wrong n that normally its the cable issue but in that case it will stay hard always where as i am facing this issue on cold start, i.e at morning time, rest of the day, either it doesnt happens or it works after few tries
i asked another mechanic, he also said, keep it in D, pull handbrake then shift to P n then turn off the car, i did that but still issue remained, he said if issue goes away then its the cable which it didnt, he said otherwise its the button issue, i havent gone to him either for the check up
sometimes at night like even tonight, i went some where, when i started car at home, it was fine but when i started the car there even if after 5min, sometimes it just wont work n requires several tries of even starting car again, today it worked again after some 5-8 tries