I have no idea how these duplicates came to be:
How do I return things to normal?
Use the Tags browser. Select the tag(s) and Delete comes up - on a tablet or PC.
Now on a mobile, because of restricted space you just see a narrow white bar - between the 3 dots and the ‘X’ . That’s the delete function!
EDIT (found the screenshot function on my phone)
@mike - hardly intuitive, would be better included in the 3 dots menu?
Thx much. Know why these pop up?
No idea. It hasn’t happened to me.