I ran into this recently in a TODO list. I’d swapped back and forth between - and * without noticing as I appended to the list. vim-markdown rendered them as a single list, but GitHub rendered it as multiple lists (fix).
Edit: @ngoldbaum in asked in chat what CommonMark does. It creates multiple lists.
Every markdown article deserves a link to Ingo’s comments on Markdown.
This might deserve its own top level post :)
We talked about it!