**JonDavis99**and **NotSoAccurateNo1**thanks a lot for your comments.
Disabling Auto Exposure from the Project Settings worked perfectly. It fixes the issue as seen in the images below.
Auto Exposure ON
Auto Exposure OFF
This level was based on the Default Level creation without any Postprocess Volume or any other settings of any kind. Just a test to reproduce the problem in a clean environment.
Thanks a lot
frank