I just Evolve my Delta bergmite few minutes ago. My Delta bergmite was first pokémon in my team and it correctly follows me, but since it was evolving in Delta Avalug, whereas he is always at the first place of my team, it is like i have no pokémon who follows me, its sprite is invisible. I try to change zone, to change pokémon, to enter in center pokémon and heal my team, but he is always invisible. ( sorry for my english i am french )
The Delta Avalugg sprite line shouldn’'t be in the game yet. A few other deltas also don’t have follower sprites.