Adding space() to BeginHorizontal() causes extra vertical spacing after certain amount.

I am working on a custom editor for a heirarchy of military unit structure. For each subunit of a given unit I display a new line in the list and indent it by the depth of the unit in the structure. You can see that in the image for more clarity.

I am noticing a behavior with EditorGUILayout.BeginHorizontal() where after applying a certain amount of space on a line there is extra vertical space occuring like something is trying to wrap because of the ‘indent’. However, the furthest right thing in the horizontal layout is a GUILayout.FlexibleSpace(). I can’t for the life of me find out what is causing the extra padding. When I reduce the indent amount added per line it works as expected with nothing extra vertically. I can determine based on the level and indent added per level that the Space() value is 40.

Here is a simplified script with the EditorGUILayout/GUILayout calls being made. Also note that the call is recursive to handle the subordinate units.

 private void UnitLine(string parent, string unit, int level)
            var unitComp = _unitMap[unit];
            EGL.Space(level * 10);
            EGL.BeginHorizontal(, GL.ExpandHeight(false), GL.ExpandWidth(true));
            var doFoldout = _foldoutOpen.GetValueOrDefault(unit, false);
            _foldoutOpen[unit] = EGL.Foldout(doFoldout, "");
            if (GL.Button("E"))
                _activeEditUnit = unit;

            if (GL.Button("S"))
                var newUnit = new UnitComposition
                    Id = Guid.NewGuid().ToString()
                _unitMap[newUnit.Id] = newUnit;
                _foldoutOpen[newUnit.Id] = false;
                if (unitComp.Subordinates == null)
                    unitComp.Subordinates = new List<string>();

            if (GL.Button("D"))
                _markedForDelete = unit;
                _markedForDeleteParent = parent;
            EGL.LabelField($"Name: {unitComp.Name}", GL.ExpandWidth(false));
            if (unitComp.Subordinates is not {Count: > 0} || !_foldoutOpen.ContainsKey(unit) || !_foldoutOpen[unit]) return;
            foreach (var subordinate in unitComp.Subordinates)
                UnitLine(unit, subordinate, level);

Here is an image of what I am seeing.197079-bad-space.png