The Pending Points cockpit setting makes it so that a guest's points lag behind for a time (one hour, for example) before they are added to the guest's total. This will allow the system to account for any adjustments made to the receipt, ensuring that your guests earn the correct amount of points and are not awarded for items they didn't purchase.
When this setting is turned on, future test barcode checkin may not be recognized. To get around this for testing purposes create a segment that includes just 1 person: you. This will allow you to activate your campaign immediately and test it for yourself without impacting guests.