[Update 01-09-2018] The problem seems to be resolved.
Recently I’ve noticed that the ETOPS app generates a message telling you that the NAT Track message is out of date. It seems to revert back to a NAT Track message of 2018-08-11. After some investigation it seems that the DINS (Defense Internet Notam System) is the cause of this. For some reason it returns the NAT Track Message of 2018-08-11. This seems to be completely random, and it also might give you the correct track message. For the moment this is out of my control.