There are 2 places to check for who the service runs as /usr/lib/systemd/system/minidlna.service /usr/lib/tmpfiles.d/minidlna.conf The lazy way is to run as root
ive got the same problem too. library doesnt update. ive tried to add media_dir= but it wont add. it will show the first library. any suggestions guys. thanks
found the solution, tried this solution found in other thread. removed the files.db in the /var/cache/minidlna folder, when you restart minidlna, it will create the file back. hope this helps.