I only used Plex to access local media from the computer in another room on the TV. Plex seemed to actively work against such uses and got progressively worse for me.

Now use Jellyfin, which was difficult because our hisense tv only had Plex (had to 'hack' it to sideload), but at the server end (just a desktop running Kubuntu in the same subnet) has been great. Works well for me, just as Plex did 10(?) years ago.