Hi Jeremiah,
If you look at the following lesson -
https://french.kwiziq.com/revision/grammar/when-to-use-cest-or-il-est-elle-est-to-say-it-is
and in particular the Q&A section at the bottom of it, you will see that this has been a hot topic...
Take particular heed of the answers from our team marked correct as it is a tricky subject.
Hope this helps