Why does plex not work unless my desktop PC is running, even wehn my NAS is on 24/7?

So I converted my old PC into a NAS this past week using Truenas community edition. I created the pool where I have my movies and transferred the movies to the NAS itself. The Plex media app is installed on the truenas GUI on the browser and I properly routed the plex app to where the movies are on the NAS. However, when I try watching from my TV on the apple TV plex app, I lose connection to the server once my DESKTOP PC goes to sleep or turns off. Has anyone run into this issue? What did I potentially do wrong?