Hello,
I’m having this problem at home:
I have installed Plex media server in my PC and I watch Plex in my Samsung TV which is in the same network as my PC. Everything was fine in the past, but now I’m facing this problem: In the morning when I launch my TV to watch Plex, it tells that can’t connect to my PC and it seems unavailable. The only fix that helps is to sign out from my Plex in TV and then link my PC to TV again using this website: https://www.plex.tv/link/
And in my PC server settings, in authorized devices, I see several devices of my TV: