I just published a new version of flarum/tags to fix the sub tag issue (flarum/core#2895).
Check that you are on Flarum v1.0.2 by running:
php flarum -V
If it reads v1.0.2 you can simply upgrade using:
composer update flarum/tags --prefer-dist --no-dev -a
php flarum cache:clear
This change has been deployed to discuss.
Thanks to @SychO for jumping on this nuisance so quickly and creating a PR to remedy it 🤟
BedsideNinja thanks for reminding me; yeah I still plan on creating a video, I'm not sure it will be a livestream yet as I'd like to go over the features of the stable product in one go. With all that is going on, I really need some time to sit down and prep a content plan for that.