If you answer the following questions, I might be able to better help you.
Are those boots old/used or new? Are the bindings old/used? Does your boot wiggle when in the binding? Does it happen/feel loose when you switch your skis around? Are any of the mounting screws loose/can you lift parts of the toe/heel off the ski? Have you had your bindings inspected by a trained shop tech this season/ever?
DO NOT TOUCH YOUR DIN, it is most likely NOT your DIN setting.
boots: new from last year
bindings: starting their 3rd season, Not loose at all, No my boots do not move in the binding. they have not been inspected this season. The din is at 7 and my marker griffons which I just had mounted were set to 8
I tail tapped a gaper who was standing on the knuckle yesterday. It was a nice firm smack right to the helmet, definitely the high point of my day.
3 dudes living together with a ferret...really hope I don't end up like that when I'm 30.
****List of Things i want****
The difference between a 7 and an 8 are not enough to cause that. I'm guessing your forward pressure is off, sometimes you wear down the toe of the boot slightly and this causes the forward pressure to be off, causing a pre-release. I recommend you take them to a shop and have them look at it.
If it's not that, it's cause you're not popping (but it looks to me in the video that it's happening as you set the edge).