In this tutorial I explained how to rename your pokemons in PokemonGo using circled numbers on iPhone x without any issues. Actually, this method is not restricted only to PokemonGo it actually works perfectly with any app on your iPhone for example you can replace your normal bullet points in notes with these circled numbers. The only down side for this method is that you have to do every step manually from 1 to 6 for each number you desire in order for this to work out. However, once you have registered all the numbers you desire then nothing will bother you again. As you can see I have chosen number 15 to be in black circle to stand out from the other low IVs because it is the highest possible IV in PokemonGo.
This is the link for the circled numbers I