Since I updated 2 days ago none of my Pokémon will evolve Scyther, Anorith, Caterpie just to name a few. I deleted the app and reinstalled it that didn’t help! And yes, they are all ready to evolve! When I hit the evolve button it takes me back to the Pokémon screen!
This is a UI bug that I have experienced myself. Essentially, the exit button slightly overlaps the evolve button. As a result, trying to evolve a Pokémon will exit the screen rather than evolving.
The following are solutions to get past this bug:
- Press the far left side of the evolve button (credits to @Amy B)
- Scroll until the evolve button is no longer parallel with the exit button.