That’s usually the correct location, when speaking about GUI file explorer.
Either that is an error or a pathetic atempt to make the pluggables “more accessible”.
Confirming that /dev/sda1 is mounted on /mnt/Data500.
Other Locations is just a fancy way of displaying pluggable drives in the file explorer. It has nothing to do with how the media is actually mounted.
sudo mount -o remount,rw /dev/sda1 /home/brian/mnt/Data500