LoRa device loses downlink functionality over time

Product/components used and version/fix level:

Product: Cumulocity Cloud - 1020.552.0
Protocol: LoRaWan
Network Provider: Loriot/LoriotAgent - 1.4.0

Detailed explanation of the problem:

We have registered a device via LoriotAgent on Cumulocity. After the registration we set the “Required interval” on the device. After the setting the “Required Interval” 3 new properties (fragments) are created on the device (managed object):

    "c8y_Connection": {
            "status": "CONNECTED"
    },
    "c8y_RequiredAvailability": {
        "responseInterval": 6
    },
    "c8y_Availability": {
        "lastMessage": "2024-11-05T14:08:46.063Z",
        "status": "AVAILABLE"
    },

The device works as expected, we receive data from the device and we can send configuration to the device.
If the device is now deactivated by an user and no longer sends data at the specified interval, the value c8y_Availability.status is set to UNAVAILABLE. At some point, the value c8y_Connection.status is also set to DISCONNECTED.
When the device is switched on again and sends data in the interval, the value c8y_Availability.status is set to AVAILABLE again. However, the value c8y_Connection.status remains DISCONNECTED and from then on it is no longer possible to send configuration to the device.

    "c8y_Connection": {
            "status": "DISCONNECTED"
    },
    "c8y_RequiredAvailability": {
        "responseInterval": 6
    },
    "c8y_Availability": {
        "lastMessage": "2024-11-05T18:08:46.063Z",
        "status": "AVAILABLE"
    },

I have tried so many things to get the device back to c8y_Connection.status CONNECTED. However, the only thing that worked to restore the downlink function was to delete the device and create it again. But this is not a solution.

My Questions:

  1. How does connectivity work?
  2. Is there any relation at all between the DISCONNECTED status and the loss of downlink functionality?
  3. Which service is responsible for the value c8y_Connection.status?
  4. Why is the c8y_Connection not set to CONNECTED, although the device sends again in the interval?
  5. Do you know a workaround to restore the device to CONNECTED status?