[john3voltas]

I beg to differ.
I have previously explained a command line method to assess the file encoding and how to convert it to UTF-8.
If Kodi has a built-in method to do that and it is available to the addon developers, that I am not aware of.
In case the previous assessment is false, if these aforementioned command line utilities are all available on any platform that Kodi can run on, that I am also not aware of.

A quick update to @"DaLanik": yesterday evening I tried the same tv show with the same sub addon provider (LegendasDivx) and I noticed that the sub that I had used before in fact shows these artifacts that I had mentioned before. I will now check the file encoding for that sub.
I also noticed that there is another sub available on addon provider OpenSubtitles.org which works just fine and does not show such artifacts.
Later today I will try to get those subs and post them here. Maybe we'll end up finding out that the sub which shows artifacts is already in a different encoding and the one that works fine is in UTF-8.
Thanks for your support.
Cheers