It is because those fields are not actually the post description, but custom fields. I have selected them for you in the search settings: https://i.imgur.com/kIwE7Ac.png
I have also made that field as the scondary post description field, in case the actual description field is empty: https://i.imgur.com/T2TeuES.png
Now searching the items will also display the description as expected: https://i.imgur.com/8y8u5pg.png
