Some tex code occurs error: \text{...} or \begin{cases}

I guess that one of \text{…} or \begin{cases} is cause.

my issue.md:

web page:
https://freshrimpsushi.github.io/hugo-issue/

I expected:
image

enviroment:

go version go1.15.6 windows/amd64
Hugo Static Site Generator v0.80.0-792EF0F4 windows/amd64 BuildDate: 2020-12-31T13:37:57Z