I'm using Samsung Note 10. I just try it and found how to make it work for sure. You see the auto replace words when you type anything ( the thing above the keyboard to help you fix mistaken words or show the rest of the word you want ) When you type the name, click on it than press enter ( it work for me right away like that )
Also, It can go throw if you put space at the end ( though, for me it delete the name but it make me start the game ^^; )
I didn't save the name, I just start and put the name there ^^
Hope this help =)