It’s a minor issue, but this is still happening with the ordered and unordered list items:
I’m guessing there’s a call to setSelectionRange that needs to have its start value offset by the length of the markdown syntax (“*” or “1.”) + 1 for the space character.
I don’t think I’d ever used those tool buttons before today. I only noticed the issue because I needed an example of a markdown editor to copy. I wonder how much actual use those buttons get?