I know why and I've done this mistake myself and I've corrected the issue.
I agree with the above, but I see another more significant issue. Your hips shoot back almost as soon as you ascend. This usually leads to issues once out of the hole. If taken to an extreme, it can even lead to falling backwards on heavy attempts. It can sometimes be attributed to weak quads.
The main thing I did was use a couple different cues:
1) Rigid shins and knees. This will help maintain their engagement and help stop the knees from going back too soon
2) The other one is to try to punch my hips forward. This helps keep the hips from shooting back. From the beginning of the ascent, the only horizontal direction the hips should go is forward.
If the cues in and of themselves don't work, you might need to do some assistance work to address the issue. Front squats work well for this because if you try to do the same thing there, you'll dump the bar forward. SSB squat would work okay too. This issues can also be caused by an imbalance between the p-chain and quads so some directed quad work might help too.
But give the cues above a try first for a few sessions and see if that by itself doesn't iron out the issue.
Way to grind through it!