If you have been disconnected from a PvP battle, please force close the app, stabilize your connection, and then relaunch Jurassic World Alive. Please note that battles will require you to use a strong internet connection with no interruptions since you will be against other opponents from around the world. 
If you are disconnected from the game during a battle, the game will continue fighting for you. This is to prevent an automatic loss or forfeit and give you an opportunity to rejoin the battle. If you are able to relaunch the game within a couple minutes, you will be able to reenter the battle you were disconnected from.