This is the note on the website, which specifically mentions the 1400-IP:
On March 1, 2017, it appears that Amazon Web Services changed how the ObserverIP opens and closes ports on the server. This only occurs on the WS-1400-IP system. This causes other tasks to slow down, and manifests itself in the indoor temperature-humidity-barometer to act sporadically. We are working on resolving the issue. Any updates will be posted on this page.