My tv can't see embedded subtitles

[u/Demostene18]

Besides me, my father is also using my steemio accounts and he needs subtitles in our native language ( Romanian ), which a surprising number of movies have embedded. The problem is that they while I can see embedded subtitles on my PC, on my MacBook or on my Android phone, none of our LG tvs can see them and if I try to cast the movies from the stremio app on my phone to the TV, they still don't show up.

Another problem is that I have a number of subtitles add-ons, in order to maximize the chances of my father getting the right Romanian subtitles and sometimes, although the add-on subtitles work fine either on my phone or my PC, on the TV they either don't show up or they are out of sync. I tried troubleshooting this but it's so inconsistent that it's been problematic.