New Server on Ubuntu randomly vanishes.

Moving my server off windows and onto Ubuntu. More or less moving along fine until after rebooting after a crash. I load up Plex and it prompts me as if it's my first time logging and and create a generic Plex-PC server. Server that I had been setting up is shown as offline.

Frustrating. Eventually say fine, I'll just rebuild. BUT the generic plex-pc when pointed at my folders won't add any media. Frustrated I take care of other projects and come back to it a few days later. Boots up and old server with all my media is back. Works great for a few days until on a reboot we're back to the generic server and my main server as offline.

Any thoughts what might be causing this?