Without being able to reproduce this on my end, it leads me to believe that there could be an issue with your specific setup, or there is a Steam issue that will need to be resolved by Valve. If after getting in touch with Valve it is deemed to be an issue with Unreal, feel free to leave a comment to reopen this thread. However, at the current time, we do not believe that this is a bug with the Unreal Engine.
Have a great day