Mathjax makes the closest bullet point disappears

[qqq89513]

For example I have a markdown file:

1. First point  
2. Second point  
3. Third point  
4. Fourth point  
    $$
    y=ax+b
    $$
5. Fifth point  

What I expected to see:

What actually rendered:

I've tried different combinations of indentation and I find out that this markdown renders what I expected:

1. First point  
2. Second point  
3. Third point  
4. Fourth point  
4.
    $$
    y=ax+b
    $$
5. Fifth point