Hi @Lucien_MILLET ,
Thanks for your post and welcome to the Cesium community.
As @ZhefengJin alluded to, your initial issue of the zoom not working may be the result of using a relatively older version of Cesium. 1.105 is over 2 years old and there may have been breaking changes to the library depending on your use case. Likewise, switching to 1.130 may require updates to your code for the same reason, thus the whitescreen you received.
It is also possible using Cesium within a Jupyter notebook is the source of your issue. There are some other threads on the forums discussing attempts to use Cesium within Jupyter and limitations folks encountered Using cesium.js within Jupyter, web workers do not terminate, leaking resources - #4 by Marc_Allen As far as I am aware using CesiumJS with Jupyter is not a common use case so I am not sure to what extent features will be supported.
We have several examples of trackedEntity in our sandcastle gallery Cesium Sandcastle
I hope this is helpful pointing you in the right direction. Please let us know if you are able to make progress with your desired use case.
Thanks,
Luke