I don't know why this occurs but if you ever plan on speed running this game here's something to keep in mind:

DO. NOT. MAX. OUT. THE. CHARACTERS. USEABLE. IN. THE. NAME. ENTRY.

I'm not sure why but as you can see in the video below if you fill in a name that reaches the maximum amount of characters you can input at the title screen the game simply resets as soon as you load into a battle and can completely stop you from speed running the game.

put: If you have to speed run it please just leave the name the default template or keep the name short and sweet so this glitch doesn't occur.