The game is glitchy.

First of all, make sure you are on the latest update. 

Ensure you have no other games or apps running in the background of your device.
You need a solid wifi connection too.

If you are on an older phone, the processor may struggle with what the game demands.

Some older phones will struggle...old phones don't see or understand the new technology needed to make these games run.

You can also turn down your graphics settings a notch or two if needed.
Tap on Settings, then Graphics. Alot of the options can help when you turn them down.

We are constantly trying to optimize the gameplay with each update.