why does my Corolla plus sport shake when I stop while driving ?is it a concern?

when I take it to maitanence I tell the person who rings me up and he said its normal I was like ? umm ok I mean the car runs fine and everything but I don't like that vibration shake it does when ever I stop at a light for over a min . they check it and tell me everything is fine it's a brand new 2015 car with only 19,000 miles I just had it for a bit over a year I don't think it should be doing that

well,i can tell you it's not normal and so will everyone else on here. take it by a trusted,independent repair shop and ask someone to drive it(you ride with em) see what they think..don't tell them what the dealer said until they give you an answer of what they think.