Again DW2-Wi-Fi sensors are offline

If you remember last year in February we have the same problem all WiFi door sensors ware offline. Now almost a year has passed and again we have those sensor down.
I wonder if they haven’t learned anything from what happened? I tried to change batteries, repairing sensors but the sensors remained offline.
All DW2-Wi-Fi sensors are offline #526970
How are yours?

My DW2 still works hmm…

Interesting, thanks!