If your Snoop Plus payment fails, you’ll have a ‘grace period’ where you’ll still be able to access Plus whilst Apple or Google retry the payment. If you’re on an iOS device this period is 16 days and if you’re on an Android device this period is 7 days for a monthly subscription and 14 days for an annual subscription.
After the grace period, you might lose access to the subscription but Apple/Google will still try to take the payment for a while. This period is 60 days for Apple and 30 days for Google.