In theory, the "NEW" should only flash (or blink) when there are phone numbers in any of the lists (OUT, IN, BLOCK) that have not been reviewed. If after reviewing all the phone numbers on these lists, your device keeps showing the "NEW" flashing, we urge you to disregard this 'NEW' alert as it does not affect the functionality of this device. Yes, it's a bit annoying but please remember that the main function of this device is to help you block unwanted calls.
We know that it is somewhat related to the caller id information sent by some phone carriers (both VoIP & PSTN). In a few cases this 'new' may be linked to the messages in virtual voicemail services. This depends on your phone service provider's implementation of the voicemail.