There has been issues with the Android version recently. Have you tried uninstalling the current PRO app from your phone and installing the newest version?
(https://www.pokemonrevolution.net/download.php)
Did you delete the previous PRO from your device before installing? I had the whole crash while starting a battle issue yesterday.
I'm on Android 8.0.0 on a OnePlus3
" We're sorry for any inconvenience this causes however we recommend that you don't play using mobile devices for the time being " - PRO Team.
Just leave the Android version until its fixed