I write in the forum in English because in Spanish two months ago I have the problem and nobody answers.
The problem that I have since November is that the default audio of the movies and dual series is set to English. In the settings you put Spanish and still coming out in English, there is no way to fix it. The server is all in Spanish and the settings of the friends you put in Spanish, the predefined Spanish audio and take the second language that is English.
It happens to me in synology and it’s not a server problem, because in another one I installed to test the same thing happens.
It is a very serious mistake please, someone help me or fix this problem please.