Steps to reproduce
In Obsidian 1.13 or above
Insert the following into a file:
$a$
- $b$
Results
$a$ renders correctly:

$b$renders incorrectly:
HTML inspection shows that$a$ is rendered correctly as:
<span class="cm-math cm-variable-2" spellcheck="false">a</span>
$b$ is rendered incorrectly as:
<span class="cm-formatting cm-formatting-list cm-formatting-list-ul cm-list-1 cm-math cm-variable-2" spellcheck="false">b</span>
Environment
1.13.3
