Ok, so I changed the status interval to 600 and nothing seemed to change. I enabled debug and found that roughly every 30 minutes there’s a CoIoT message reporting the temperature (along with a couple of other items in the log), then a few minutes later there’s a single entry in the log where the temperature value of zero is recorded (log entries relating to the thing only below):
2022-12-03 21:03:00.692 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Message from /192.168.1.87:5683 (MID=353): {"G":[[0,3101,11.3],[0,3102,52.3],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]}
2022-12-03 21:03:00.692 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Sensor data {"G":[[0,3101,11.3],[0,3102,52.3],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]} (serial=353)
2022-12-03 21:03:00.692 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 9 CoAP sensor updates received
2022-12-03 21:03:00.694 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 11.3 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 21:03:00.694 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 2 channels updated from CoIoT status, serial=353
2022-12-03 21:05:35.559 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 0 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 21:33:01.717 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Message from /192.168.1.87:5683 (MID=354): {"G":[[0,3101,11.1],[0,3102,52.0],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]}
2022-12-03 21:33:01.717 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Sensor data {"G":[[0,3101,11.1],[0,3102,52.0],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]} (serial=354)
2022-12-03 21:33:01.718 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 9 CoAP sensor updates received
2022-12-03 21:33:01.719 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 11.1 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 21:33:01.720 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 3 channels updated from CoIoT status, serial=354
2022-12-03 21:35:38.924 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 0 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 22:04:00.717 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Message from /192.168.1.87:5683 (MID=355): {"G":[[0,3101,11.1],[0,3102,51.9],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]}
2022-12-03 22:04:00.718 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Sensor data {"G":[[0,3101,11.1],[0,3102,51.9],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]} (serial=355)
2022-12-03 22:04:00.718 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 9 CoAP sensor updates received
2022-12-03 22:04:00.719 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 11.1 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 22:04:00.719 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 2 channels updated from CoIoT status, serial=355
2022-12-03 22:05:42.036 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 0 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 22:34:01.705 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Message from /192.168.1.87:5683 (MID=356): {"G":[[0,3101,11.1],[0,3102,52.0],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]}
2022-12-03 22:34:01.705 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: CoIoT Sensor data {"G":[[0,3101,11.1],[0,3102,52.0],[0,6107,0],[0,3119,1670094796],[0,3120,1],[0,6110,0],[0,3106,0],[0,3111,100],[0,9103,5]]} (serial=356)
2022-12-03 22:34:01.706 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 9 CoAP sensor updates received
2022-12-03 22:34:01.707 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 11.1 °C (type class org.openhab.core.library.types.QuantityType).
2022-12-03 22:34:01.707 [DEBUG] [elly.internal.coap.ShellyCoapHandler] - shellymotion2-8cf681107741: 2 channels updated from CoIoT status, serial=356
2022-12-03 22:35:45.379 [DEBUG] [y.internal.handler.ShellyBaseHandler] - shellymotion2-8cf681107741: Channel sensors#temperature updated with 0 °C (type class org.openhab.core.library.types.QuantityType).
Any thoughts?