After updating from Unity 2020 LTS to 2021 LTS I have encountered that Application.platform returns RuntimePlatform.WindowsEditor when I test my application in the editor instead of the OS it is supposed to simulate ( RuntimePlatform.Android or RuntimePlatform.IPhonePlayer). This worked perfectly fine in Unity 2020. Since the Device Simulator is now built into the editor I cannot reinstall the package easily. So, is there some way to fix this problem?
I found in this thread: https://forum.unity.com/threads/new-device-simulator-preview.751067/page-6 that Application.platform needs to be updated to UnityEngine.Device.Application.platform. Now it works as expected!