What model do you have?
You can use this to find the compatible formats for your media
What did you format the drive as?
i.e. fat,fat32,ntfs? etc
Drive is formatted as NTFS
Would be easier if you said which model TV you have (full model name). Mine is from 2016 and plays MKV files fine streaming from my NAS.I have a samsung smart TV and it is unable to play MKV's. Will I need to convert the MKV before I can get it to play? If so what format is the best to convert it to