Charts with 4+ levels don't group

[d3xbot]

Chart levels 1, 2, 3, and mostly 4 group together nicely. When making a larger chart (e.g. 5+ levels), a level 4 item with 2+ level 5 children will not group the child items together but instead spread them apart.

Attached is a txt file with the code I'm using to create a map of some documentation with the titles removed as an example of what I'm talking about.
demo.txt

In my testing, this occurs with the Mermaid Live editor online as well as in Typora (with Mermaid support enabled). It also occurs regardless of tabs/spaces at the start of the lines.