I've configured the project settings in Unity (see first capture image-114.jpg)
And when I play PlayFabSdk/PlayFabSDK/Testing/scenes/testscene.unity or PlayFabSdk/PlayFabSDK/Testing/Tests/Scenes/UnitTestScene.unity it resets my configuration (see second capture image-115.jpg) and the console displays a "UriFormatException: Invalid URI: The hostname could not be parsed." because it's trying to send a UnityWebRequest to "https://your title id here.playfabapi.com/Client/LoginWithEmailAddress?sdk=UnitySDK-2.79.191218" due to my config reset on play time.
I expected these scenes to serve me as example of requests to test the PlayFab service but it seems bugged :/
If I reconfigure the title at runtime for the next request retry to work it still doesn't work (same error, a matter of cache I guess)
I've created my own test scene with a script doing a Device Login like in this tutorial and it works great (no config reset, everything's ok), I guess I'll keep doing that.