After deleting the post, the statistics have not disappeared. Is this a bug? Hope to fix it!
g7net hey! Looks like you're using flarum categories, which is essentially a theme for tags. That data is a bit lagging due to a bug with the tags extension (which will be fixed in beta 14). Until then, I've included a command line command in categories that you can run to sync up the counts. https://discuss.flarum.org/d/23184-flarum-categories/111 for more info