@Jebeyer 

Thanks for all this help.  The tapo company must be happy to have such helpful private individuals.  

Thanks again and goodbye!

  @Zenoxi 

Thx. But Wayne TP is also right: see his Post#2. That's the way to go, if your are using the Kasa App. What you need in this case: KE100 + KH100 (Hub) + Sensor, for instance: T110, T310/ T315 and Kasa App.

Thats also what I'm using before switching over to the Tapo App for adding/ controlling my (4) KE100 with H100 and T110 (for window open), T310/ T315 (external Temp. Sensor)(KH100 also possible in Tapo App). But why using two hubs and apps, since Tapo H100 also supports KE100 and is working flawlessly (for 6 months now) in Tapo App.

Conclusion: KE100 is working with both apps and hubs: Tapo & Kasa. Yes, maybe not in all countries/ regions.