For LG TV you may need convert Dolby Vision MKV to MP4

mkvextract.exe input.mkv tracks 0:video.hevc 1:audio.ac3 2:en.srt 8:cs.srt
mp4muxer.exe --dv-profile 5 --input-file video.hevc --input-file audio.ac3 --output-file movie.mp4
mp4box.exe -brand mp42isom -ab dby1 -no-iod -add "movie.mp4" -add "en.srt#subtitle:lang=en-EN:name=English" -add "cs.srt#subtitle:lang=cs-CZ:name=Czech" -new "outfinal.mp4"
atomicparsley outfinal.mp4 --artwork cover.jpg
pause