Update, I just tried to temporarily disable it and run Tools - Check Database to remove unused tags. After that did not work, I tried to uninstall and install it again or then did the same with Hierarchical Tags 2. Still, it is not working.
Update, I just tried to temporarily disable it and run Tools - Check Database to remove unused tags. After that did not work, I tried to uninstall and install it again or then did the same with Hierarchical Tags 2. Still, it is not working.