Problem installing server on laptop after Linux re-installation from backup

MX bothers me but as long as it doesn’t bother – ok for now.

As for your media, Mounting NTFS for Plex to use takes a few steps.

Because of that. I have a How-To already written.
Please take a look and see if it helps.

You’re correct. Plex should not see your home directory not anything else you’ve not expressly given permission to (that’s how Linux works – ultra strict)

Here’s the link to the How-To.
Don’t hesitate to ask if you’ve any trouble following.