I have no idea whether you’re properly deadlifting or not, I can only speak from my own experience…
I was deadlifting and squatting without issue for two decades. Then I hired a legit trainer and the first thing they did was make me relearn how to deadlift and squat. I had to lower the weight by 50%, wear a rubber band around my knees, and learn how to lift/squat without an inward knee flex at the beginning of every movement. I had no idea I was doing it and wouldn’t believe the trainer till shown video evidence.
Here’s another couple good variants by the way. 1) A sumo deadlift. Just focus on flexing the knees outwards when doing deadlift. And 2) Wearing a “booty band” resistance band around the knees and hitting the abductors (my weak spot) while doing a normal deadlift. (The “booty bands” are the fabric elastic bands that don’t yank every hair off your body like the rubber bands.)