code fenced block for lua not working well

[laoshaw]

which code syntax highlighter is used by vim-markdown?

[alerque]

The code blocks should just be passed back to VIM for whatever highlighting it would do for a given filetype. Are you setting the language of your code blocks, e.g.:

```lua
local foo = true
```

[laoshaw]

yes, I made sure my .vimrc has only one Plug, that is vim-markdown, all lua files are syntax highlighted fine, but not within a markdown lua block: