[Bug] Plugin didn't switch off devices anymore
**Describe the bug**
After some time the plugin didn't switch off some devices (Shelly 1 and Shelly Dimmer 2). With a restart of the child bridge the plugin works as it should, but after some time (1-2 days), it is only able to switch on a device, but not to switch off. Device is shown as switched off, but it's still on.
In Shelly App the device status is shown correctly. 

**Log output**
Add any relevant parts from the homebridge log here, if applicable.

**Environment:**
 - Shelly device(s): [e.g. Shelly 2.5]
Shelly 1 and Shelly Dimmer 2
 - Plugin version: [e.g. 0.14.0]
 0.19.1
 - Device running homebridge: [e.g. Raspberry Pi]
under Docker on a mini pc with proxmox