Substituent of the ring can be displayed correctly in the cards, but the ring structures cannot be displayed correctly.
I’m not familiar with this package, but perhaps you can try and see other structures which are rendered properly (to ensure that it is not just the main ring issue) and then try to see the difference present in ones which render and ones which don’t.
If none of your LaTeX works – do you have it enabled in Preferences? Math & Symbols - Anki Manual
If some of it works – as SuhasK said, have you compared the cards that work with the cards that don’t? Have you, for instance, tried this LaTeX string without a cloze marker?
And if you want help with a particular LaTeX string, you should post it as text (in a preformatted-text/code-block), so folks can experiment with it.
I am sure that I turn on the Latex option.
And when I use another command, it showed a strange shape. Here is the code:
[latex]\chemfig{A=B}[/latex]
And here is the image:
I get the same with the default png version. Using .svg fixes it for me. You can change it with the checkbox here:
Thank you very much. It works on my anki.