What country are you in and what version firmware did you install
Always best to only install the firmware from the mydlink website (where you registered the device) ie I'm UK and use
https://eu.mydlink.com/ then sign in then click support (top right) then select device
Regarding your LG tv - what model? Can you see any shared folders say from your pc? (make sure you have network shares set) - if yes can you access the NAS from (for example) an android device - if yes it's most likely to be a setting on the tv - hence needing the model number.
Also note that some devices cannot play certain files types (containers) and also the NAS will be restricted in what it can/can't do (transcoding)
I have a 320L and tried various options and the best yet for me personally (everyone is different ) is having Kodi installed on several devices linked to one database (on the server) and using the "device" so that my Sony BDE3100 can access. My Sony BDE3100 can access direct via DNLA but then I'd have to recode all my new or stored media.
HTH