Welcome.
Not sure what the wide world of deadlifts is going on with your neck, but knock that off. Just point your boobs at the wall in front of you while you lock your eyes on the ground 10ft. out.
Hips looks a little low at the start, but I'd like to see your feet and shins. Also, you'll want to stop dropping the hips and nudging the bar forward when you set your back. "Squeeze" the chest up smoothly and slowly with the hips in place to set the back and avoid perturbing the bar.
Please check out the sticky at the top of the forum for how to film the deadlift. I even made a video! It's not a toktik or whatever tf the kids are watching, but considering the budget to produce, it's not bad. Help us, help you.Hopefully the camera angle is alright
Are you sure the low back soreness is from the deadlifts?