I have become champion and I have Kubfu but I still couldn’t meet Hop. If you have a solution please type it below.
If you haven't already, beat the post-game by going to the Slumbering Weald and talking to Hop there. If you haven't seen him after doing the post-game, make sure you also go to all the Kubfu sightseeing spots and then go to the Towers of Waters/Darkness. Then you should meet Hop if you have completed the post-game.
Hope this helped!