Shellys all Offline, in Shelly App OK

I am using Openhabian 2.5.9 with 7 Shelly devices. I have every day that all Shellys go offline and I can no longer switch them on or off. but everything works normally in the Shelly app. After restarting openhab, it works again for about 1 day. My log is flooded with offline messages. What can I do? I had it with all of the other previous versions too. The latest firmware is installed everywhere on the Shelly 1.8.3