You could upload a sample clip including subtitles.
What do you mean ? It does it to me on every video.
I had opposite problem with subtitles, always wanted to have original audio but specific subtitles language plus ignore forced subtitles if exists - ended up with creating my own little plugin for this
Anyways, if current (updated) settings in Kodi aren't working for you, you can install Language Preference Manager plugin, which has zillion of options so some settings here should fix your problem.
it's an old addon, It worked well before