Ready the sticky again (ideally get your entire body in the video).
Your wrists are flexed (bent over the bar). Try and keep them straight. Your stance looks a touch too narrow as well. You aren't really leaning over enough at the start and your resist the lean even more by pulling your chest up as you go down (and thus arching your back). We want the back flat. In order to retain balance when you lean over, you must send your butt back (as if reaching for an object behind you). If you do this you will feel a bit tighter in the bottom and likely remove that extra inch of depth that appears in some reps. Side note: this weight is pretty light, so you may still need to assess what is going on at heavier weights, but try and fix these areas as a start. Also, make sure you are eating enough.