In the starting deadlift form, we have to hinges : the one at knees and one at hips. I noticed in my lifts, that I unfold the knees and then separately unfold at the hips.
“Early knees” is a common cue.
“Early knees” is a common cue used among powerlifters, referring to locking your knees as early as possible in the deadlift. It’s more often used for the sumo deadlift, but I’ve seen it used for conventional ad well, and the principle applies just the same. It isn’t essential, but can be helpful if you have trouble locking out your hips before you’ve locked your knees. There is, of course, going to be a lot of individual variation here. Personally, I struggle tremendously to lockout my hips if I locked out my knees yet.
An example of an accomplished lifter with an often exaggerated early knee lockout is Yangsu Ren aka Deadlift_Panda. In this video you can see how early he locks out at the knee prior to locking it out at the top. So it isn’t “wrong” to lockout your knees early, unless it’s wrong for Yangsu Ren to do it while deadlifting over 360 kg at a body weight of 80 kg.
Like I said, there will be a lot of individual variation, and you’ve got to figure out what works for you. But early knees is not necessarily wrong or poor form.