[Koha] languages choice in Koha 3.18.1

[WisdOMbooks]

Hope this is below 40 kn !

Please, refer to these: http://turl.ca/kohalang1 AND http://turl.ca/kohalang2

In the search settings, I have selected *san,ben,hin,eng,fre,ita* (as per ISO 639-2 language codes = Sanskrit, Bengali, Hindi, English, French, Italian), as limitation to the choices for the OPAC dropdown in the Advanced Search page.
(I have also tried with the pipe separator: *san|ben|hin|eng|fre|ita*... with the same result! )
However, in the actual dropdown, the choice does not include the language Sanskrit PLUS the order is not the one of my choiceor not even an A-Z order...

Could any kind koha-expert check into this and explain why the Sanskrit language does not appear as a choice in the OPAC search dropdown? 
And why the order of the languages is not the same, as the one I have indicated in the administration?
I think we should be able to arrange the languages as per our choice and requirements or, at the very worst, in an A-Z order, for this feature to be useful to the users.

Even better, as I am seen in most of the best websites, nowadays, there should be a clickable multiple choice, not a single one! 
In such a way that, for ex., if I want to find out how many titles I have in any Indic language, I can select Sanskrit, Bengali and Hindi or, instead, if I want to know how many in any European language, I can select English, French and Italian.
This will be the best, I guess... and kindly suggest :) Thank you:

Mr. Angelo Pugliese (HeadLibrarian)
BhaktiVedanta Research Centre
Kolkata (Calcutta), India

(I am on the latest Mint server, with the latest Koha 3.18.1; client on Windows, 16 RAM)