Apple TV 4k buffering

Hi. I have been streaming wirelessly to my LG model 42LB5800 TV (non-4K) for several years now. Due to numerous problems with wireless in my home I decided to fix these problems once and for all. I installed Netgear Ethernet-over-power adapters to eliminate the wireless connection between the router and the TV and I upgraded to the 64GB Apple TV 4K appliance to get a gigabit Ethernet port and the latest and greatest in TV boxes. I just installed this equipment last week.

I have a 100 Mbps connection from my ISP.  I have tested connectivity through the Netgear connection all the way out to the Internet.  I get approximately 40 Mbps actual wired throughput from the Apple TV 4K port all the way to an Internet server and back with zero errors.   I ran a continuous 1500-byte ping test for close to an hour - 3320 packets - with zero packet loss and an average response time of 47 ms.  This should be more than enough clean bandwidth for either Netflix or DirecTV Now, which are the two apps that I use.

I thought that my video-freezing and buffering problems would be gone forever. Much to my dismay I still sporadically have a freezing/buffering problem when connecting to either Netflix or DirecTV Now. Restarting the app resolves the problem. But I had hoped not to have this problem at all anymore. W*&@#$&^!@k!   Any ideas on why I am still sporadically having these streaming issues?