Do you see ties in the picture that are not black?
No, there is a tie but it is black.
    src        edge_attr  dst
0     0   to the left of    7
1     0  to the right of   22
2     1  to the right of   18
3     1  to the right of    9
4     1  to the right of    5
5     2  to the right of   22
6     3  to the right of   18
7     4  to the right of   22
8     4  to the right of   16
9     5  to the right of    6
10    5   to the left of    1
11    6   to the left of    5
12    6           around    2
13    6  to the right of   22
14    6   to the left of    9
15    7  to the right of   18
16    7  to the right of   21
17    7               on    8
18    7  to the right of    0
19    7  to the right of    8
20    8   to the left of    7
21    9  to the right of    6
22    9  to the right of   10
23    9   to the left of    1
24   10  to the right of   22
25   10   to the left of    9
26   11  to the right of   22
27   12  to the right of   18
28   13               on   12
29   13  to the right of   18
30   14  to the right of   22
31   15  to the right of   22
32   16  to the right of   22
33   16   to the left of    4
34   17   to the left of   18
35   18   to the left of    7
36   18   to the left of   12
37   18   to the left of    1
38   18   to the left of    3
39   18   to the left of   13
40   18  to the right of   17
41   19               on   22
42   20  to the right of   22
43   21   to the left of    7
44   21  to the right of   22
45   22   to the left of   16
46   22   to the left of   15
47   22   to the left of   10
48   22   to the left of   14
49   22   to the left of   11
50   22   to the left of    2
51   22   to the left of    0
52   22   to the left of    6
53   22   to the left of    4
54   22   to the left of   21
55   22   to the left of   20