website TOC generation

Hugo/markdown automatically inserts a TOC into each page, if there are subheadings. However, I notice that depending on the nesting structure, the generated TOC looks different. Attached are 2 examples, one of which has a consistently ordered list, and the other of which is a mix of list items and ordered lists. The latter example can be reproduced consistently by inserting sub-sub-headings under any page subheading that's not the last one.

E.g.

## heading
## another heading
### a subtopic

will look fine

But

## heading
### subtopic
## another heading
### another subtopic

will not.