I have this same behavior now On my OLED55B6P. The only things that have changed:
1. Verizon replaced my optical network terminal for my Fios service.
2. I updated my TV’s firmware
I can’t correlate the timing to one vs the other since the error messages about disconnection/reconnection aren’t always there. But since you’re all having the problem too, it seems like it must be some issue with LG’s firmware.
Everything else in my networking, wiring, routers, etc. have been unchanged for years.
(Some Side rants)
With the most recent firmware update, my Simplink functionality stopped working. I can’t get my LG DVD player and audio system to turn on when I switch to my TV optical output. I requested LG support multiple times on the Simplink issue and have not heard anything. It’s very frustrating.
With the update prior to that, my smart apps have started crashing far more often than they used to.
And the damn Disney+ app, unlike every other app, refuses to let me do a zoom to avoid letter boxing on 16:9 movies. It zooms but then letter boxing remains unchanged. Mind boggling.
(End side rants)
Also, I tried a factory reset of the TV. It didn’t fix any of these issues.
This is my third LG Flatscreen TV. If this stuff can’t get resolved, it will likely be my last.