Devolo Doorcontact shows Fahrenheit instead Celcius ... (before it was fine!)

Hello,
since 3 month I have an Devolo Doorcontact (zwave), this also show the temprature.
Till 3 weeks it works fine, now I see that the Devolo is sending temperature in Fahrenheit instead Celcius.

In the Things preset there is default (1010) at option “5”, which should be correct.
But when checking in oH console it shows me “60” (Fahrenheit) instead “16” (Celcius).

Before it was fine, I can see it also in the influxdb.

Since month I did not touch this device or the configuration !

Any idea whats going wrong or where I have to “edit” the config to get back “Celcius” values?

devolo-preset

I remove it from oH and add again, but still the same.

Wondering, if I enter in parameter no. 5 the “10” to use Celsius, in the logfile I see and in the PaperUI Thing-configuration the field is empty again:

2019-01-27 17:20:45.060 [vent.ConfigStatusInfoEvent] - ConfigStatusInfo [configStatusMessages=[ConfigStatusMessage [parameterName=config_2_1, type=PENDING, messageKey=null, arguments=null, message=null, statusCode=null], ConfigStatusMessage [parameterName=config_8_1, type=PENDING, messageKey=null, arguments=null, message=null, statusCode=null], ConfigStatusMessage [parameterName=config_4_1, type=PENDING, messageKey=null, arguments=null, message=null, statusCode=null], ConfigStatusMessage [parameterName=group_2, type=PENDING, messageKey=null, arguments=null, message=null, statusCode=null]]]

Other parameters I can change and the are store, without a log entry.
But in the parameter 5 I can enter whatever, the error appear and the value is not stored (after opening again the field is empty, see screenshot)

Is the device broken?para-no5

Also wondering:
If I change in the channel-configuration the field “Dimension” from empty to “Temperature”, I see in the console as the temprature value not only the value (like: “77”), than I see “77 °C” ! So the "system think it has Celcius, no Fahrenheit (or?).! But the shown value is Fahrenheit.
devolo-temp|690x158