Yes, your deadlift may feel weaker with deviations in technique.
Some things turn off when certain things are present.

Hip flexion is one things that can impact.
It’s pass or fail 1 or 0, “passed pretty well” sounds like something is missing.

Butt Wink when squatting so this isn’t a new issue then.
Impacting another movement pattern now.
Butt wink with a squat is never ok
Pro Episode # 27 – Butt Winking Is NOT ok. Ever. (So don’t you even think it.)

Starting over extended.
Bone on bone overextended pelvic position.
The femur runs into the pelvis. Then reverses.
Second over extension on the way back up.