First item in inspector list is incorrect height

I created a custom property drawer like so:

 using UnityEditor;
 using UnityEngine;
 
 [CustomPropertyDrawer(typeof(DialogLine))]
 public class DialogLinePropertyDrawer : PropertyDrawer
 {
     private const int Padding = 5;
     
     
     public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
     {
         // Calculate reusable values
         var start = position.x;
         var top = position.y;
         var half = position.width / 2.0f;
         var line = EditorGUIUtility.singleLineHeight;
         
         
         // Draw fields - pass GUIContent.none to each so they are drawn without labels
         var speakerRect = new Rect(start, top, half, line);
         EditorGUI.PropertyField(speakerRect, property.FindPropertyRelative("speaker"), GUIContent.none);
 
         var clipRect = new Rect(start + half, top, half, line);
         EditorGUI.PropertyField(clipRect, property.FindPropertyRelative("clip"), GUIContent.none);
 
         var emotionRect = new Rect(start, top + line + Padding, half, line);
         EditorGUI.PropertyField(emotionRect, property.FindPropertyRelative("emotion"), GUIContent.none);
 
         var positionRect = new Rect(start + half, top + line + Padding, half, line);
         EditorGUI.PropertyField(positionRect, property.FindPropertyRelative("position"), GUIContent.none);
 
         var textRect = new Rect(start, top + (line + Padding) * 2, position.width, line * 2);
         EditorGUI.PropertyField(textRect, property.FindPropertyRelative("text"), GUIContent.none);
 
     }
     
     public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
     {
         return EditorGUIUtility.singleLineHeight * 4 + Padding * 4;
     }
 }

It works as expected, except the first item in a list of that type always displays with the incorrect height. (See the image below and how the first item renders partially behind the second one.)

Is there something wrong with my code or a workaround I can use to fix this?