Sometimes the easiest way to resolve an issue is to force-restart the game. In order to do this you need to close the application from any multi-tasking menu before relaunching it. Follow the steps below to accomplish this:
iOS Platform:
https://support.apple.com/en-us/HT201330
Android Platform:
https://www.wikihow.tech/Force-Quit-Apps-on-Android
If these guides do not help, or if you encounter any issues attempting to force-close the game, feel free to submit a ticket.