The issue here is that we are parameterizing the tag name here which strips special characters from strings. This also means that tags with emoji in name will show same behaviour.
The fix is pretty simple (PR):
https://github.com/discourse/discourse/pull/9839
But I am not sure of the side effects of removing parameterizing. The interesting thing is it was I who added parameterization two years ago in:
https://github.com/discourse/discourse/commit/18f50ca01abfa5497b3dc423470c3b5e84e48771
But not sure what issue it was fixing.
I have tested the PR pretty rigorously locally and I don’t see any issue with removing parameterizing of tag names.
EDIT: PR is merged.