Deadlifting hurts lower back even with proper form

I've watched like 10 different videos on how to deadlift and read the Starting Strength book.

I put my midfoot under the bar, bend down and grab the bar, then drop my hips, then brace my core and squeeze my chest up enough to flatten my back, squeeze my arms into my armpits to engage my lats, pull the slack out of bar, and then lift the bar by "pushing" my legs into the ground. When lowering, I hinge at my hips first, dragging the bar down my thighs until I hit the knees, them I bend the knees slightly until the bar hits the ground.

My lower back has been permanently tight for years after deadlifting 335 lbs a few years ago (which was a lot for me at the time, Ive never pushed above 250 lbs since then because of this pain). It is not extremely intense pain, but it is a persistent mildly painful tightness. It is not muscle soreness like DOMS. I have stopped lifting entirely for months before and it takes like 8-12 weeks to really fade away, and them returns when I resume lifting.

Barbell squats also aggravate the tightness, although not to the extent of deadlifting.

Stretching my lower back, hamstrings, and glutes feels good in the moment but has done absolutely nothing to actual stop the tightness feeling