Oh man. I didn’t remember setting Plex in 192. Sorry. Unraid is new to me and there’s been a ton of testing and reconfiguration. But I’m not sure VLAN is the root of the issue. I just turned on the config you suggested and Plex stopped on first song I tried.
I really appreciate all your time, but I’m afraid I’ve wasted it. I’ve come full circle. I’m positive the issue was Sonos. I mentioned it before but they released an app in May that completely changed everything about the UI, feature set, and even how the speakers connect to the network. They went from rock solid dependable to bricks overnight. Sonos streams remotely so the VLAN explanation just didn’t make sense to me. So I gave in and completely reset all my Sonos devices and reconfigured everything as if it was all brand new and changed how the devices connect. I probably should have just started with that. I’ve listened for hours last night and this morning with no noticeable issues.