luceos post once in each tag and then delete that discussion. That should fix it. One could also create a command to recount programmatically, what approach would you prefer?
It doesn't work for me, I made an import MyBB to Flarum and discussion_count column in tags table is empty, so I can't show forum statistic using extension.
I tried to create a post and counter show 1, after I delete it the counter shows 0 posts in that tag, even though there are a few thousand of them.
Do you have any suggestions on how to re-count posts in tags?