Today I went to launch and 4 times in a row, the drone would start to launch and immediately do a backflip off the plastic case I launch it from and land upside down, breaking a prop at one point. Seems like perhaps 2 of the rotors are not kicking on right away or with enough strength and the other two cause it to flip backwards. Any ideas, drone gurus? Got a big day tomorrow and I need to figure this out. Thank you in advance!