It will be triggered again when you go out of range and back in range of the beacon. What you're experiencing is related to iOS specific behaviour - iOS does not report that the device has left the range of a beacon until its signal remains undetected for long enough to rule out temporary physical interference with the Bluetooth low-energy radio signal. Try switching the beacon off, waiting for about 20-30 seconds and switching it back on. If you switch it on before that time iOS thinks that you haven't actually left the beacon - hence not receiving an event.
As you're already using Cocoapods to manage your dependencies, the best solution would be for you to stop using the Segment.io library we provided and pull Segment.io yourselves via Cocoapods instead. Cocoapods is smart enough to manage the clash with Reachability itself and 'do the right thing'. You'll need to add the following line into your Podfile for your application target:
Then in the Link Binary With Libraries build phase of your Xcode project you should remove our 'Segmentio.framework' library as it's no longer required. The application will then link without issue.
pod 'Analytics', '3.1.0'
By embedding Segment 3.0.0 or above into your application, we will be able to provide you with data analytics enhanced with the specific location where an interaction took place.