[sumaiazaman]

wherePivotBetween() only adds its constraint to the relationship's select query. Unlike wherePivot(), wherePivotIn() and wherePivotNull(), it isn't recorded for newPivotQuery(), so pivot table operations run without it.

This can delete data. Given a relation scoped to one year:

public function tags2026()
{
    return $this->belongsToMany(Tag::class)->withPivot('year')->wherePivotBetween('year', [2026, 2026]);
}

$post->tags2026()->sync([4]);

sync() treats the tags from every year as currently attached, so it also detaches the 2024 and 2025 rows. detach() with no arguments removes all of the post's tags, and updateExistingPivot() updates rows outside the range.

This records the wherePivotBetween() arguments the same way wherePivotIn() does and applies them in newPivotQuery(), which also covers orWherePivotBetween() and the NotBetween variants. It's the same kind of issue #61488 fixed for wherePivot() closures.