Before trying to delete the app like others mentioned, you might try this… Most smart phones and tablets have a way to shut down background apps, or to power off the device completely and have it reboot. I would try that first.
I had one game on my phone that would behave very weirdly. It had a countdown timer and the timer would drop from 3 minutes to 0 in about 10-15 seconds. You would see 3:00 then 2:47 then 2:12, and so on. Doing a power off and then back on fixed that issue.
On an iPhone or Samsung Galaxy, you should be able to just press and hold the power button and it will ask for confirmation to “power off”. Then you just press and hold the power button again until the screen lights up. You’ll get the device startup logo, and then you log back in and try the game again.