Yesterday WiFi door sensors had issues. They all appeared as offline in your device list in the app.
The first report on this issue came in at the eWeLink official Telegram group at November 12th, 2020 at 12:59 (UTC+1). At that moment it seemed to be an individual case. At 17:21 (UTTC+1) more reports started to come in. On the eWeLink & Sonoff User Group also several people reported the issue. Several new posts and comments about the issue were posted.
All together as a community we investigated the issue. At first the issue seemed to occur after a recent firmware update. Then people started to test with brand new WiFi door sensors as well WiFi door sensors that have never been updates. All showed offline.
It turned out to be a server issue and eWeLink fixed it at Friday 13 November 2020 around 6:00 (UTC+1).