How do I fix continuous Apple TV 4K streaming cut-outs from iTunes computer Library?

I regularly stream from my Desktop Apple Library to Apple TV 4K throughout the house (3 Units) and rarely have a problem. Within the last 3-4 weeks, attempting to stream movies from the computer library playlists results in an error stating the TV can't connect and to connect to the Apple TV live streamer. This happens after anywhere between 30 minutes to 4/5 hours into streaming. I have never seen this error before, and it will disappear after about 10 seconds. Then, the Library will come back up, and I can stream again.

This is most prevalent with Movies, but also somewhat less so with TV shows.

I have reset all three boxes, reset the Modem and Router (both supplied through Spectrum), and done this multiple times, and yet the problem still persists. Latest updates on iTunes (last week - 12.13.7.1) and Apple TVs (last week also.) The problem predates those updates by about a week or two.

[Re-Titled by Moderator]