HTML 4.0 Transitional -- or -- Language thingy?

I am new to Select2 and noticed it works well in the English section of the site (coded in HTML 4.0 Transitional) but in the same site – in French and German it is not working properly. One can not select from the drop downs. Is this a Language issues, or an HTML 4 issues? Thanks.
works: https://www.filmfix.ch/v3/en/16mm-transfer/
is not working:
https://www.filmfix.ch/v3/de-ch/16mm-transfer/

I found the problem. Some code above the select2.css file prevented the .css file from loading when the language was set to French and German.