Preview does not match post; Post is unstyled

The preview looks great, but the post is not styled at all. If I add the “dataTable” class to the table on the post using my browser’s inspector, the styling applies correctly and the table looks great.

Also, I merged 2 cells in the editor, looks good in preview but they are not merged on the website. The cell (A3) has data-rowspan=2 but but not rowspan=2.

https://www.sacvalleyorchards.com/pest-reports/spider-mites/