Plex can’t access secondary drive in Ubuntu 18.04

I am in the middle of setting my Dad up with a new computer (Asrock Deskmini) Ubuntu 18.04 and recreating the Plex media server on this one before Christmas.

I added 2 internal drives to give him more media storage for Plex for when i add movies to mine i can copy them to his. I software raided (2) 2tb drives that i had in a Raid 0 for 4 tb’s of storage. (These are just copy’s from my system which had 2 copy’s both in separate raid 5 arrays so i don’t need the extra info about redundancy). This raid drive is ext4 format also.

The drive works great but i can’t seam to get Plex to see the internal folders of the drive. I added Plex to usergroup “plugdev” and “Myusergroup” with no avail.

I think the problem I’m having is mounting the drive in /home/dad/Plex. In the drive there is already a “Movie” folder and “Music” and my kids “Football games” folder. I tried to modify the mount point inside the GUI in disk’s then clicking on the Gear. I change the mount in there to that location and then i have no access to the drive even after reboot. I tried to make the change by editing the Fstab file and same thing.

Should i set it to somewhere else?
Please help i want to get this to my dad for Christmas.