10-06-2019 06:13 PM - edited 10-06-2019 06:15 PM
By saying Netflix and YouTube apps, you are going to the channels in the guide right? Is the HDMI cable from the box to the amp(receiver) 4K certified? Did you try to manually setup the box for your brand and model receiver? Is the input on the receiver the box is connected to set to enhanced mode? Did you try going direct from the box to the TV to see if the receiver was the problem?