Damian Delta Starter Bug

I started the game with Delta Bulbasaur, played through and got Delta Squirtle from Professor Sylvan in the post-game, but then when I got a starter from Damian, it wasn't Charmander, but another Delta Squirtle.

I'm pretty sure this means I can't complete the Pokedex without trading (which is supposed to be possible in this game), so I'm just going to revert to a save before Damian gave me the Squirtle so I can maybe get the correct starter in a future version of the game.