Hello Menion,
it's not that difficult to find the sensor, at least in Germany. Thanks to your tip I found the sensor in question on Ebay and then entered the term "SensorBlue WS07 SMart Hygrometer". Using the images then shown in Google, I was able to find various suppliers of this sensor. The only difficult thing was that the sensor appeared under different names from different suppliers. At Amazon alone, this sensor is available under at least three different names. Just compare the image of the sensor.
Since Amazon grants a right of return and does not charge any shipping costs for Prime members, the risk is relatively low.
I would also like to take this opportunity to thank you for making it possible to include the "RainToday" app in the sidebar.
I've been in navigation for a long time. I started with Oziexplorer and Pathaway over 20 years ago, then TwoNav. I tested Garmin, Komoot and OutdoorActive and ended up with Locus Map. This app is indispensable for me. In my opinion, it is the best and most versatile on the market. Now that the Samsung problem with dimming has apparently been solved thanks to a tip from the forum, I'm really perfectly happy at the moment.
The service is also good, so I'm happy to pay the annual subscription costs for the gold subscription. So once again my thanks to you and your staff.