Language filter defauts to null

How can I make the default language filter be “Display all languages”?

For a long time I thought that it was something wrong with the search setup, because I couldn’t find videos on my instance, nor with local search or global search. Then I found out that the reason was that the default language filter is set like this (null?) when I’m logged in. When I’m not, the default is “Display all languages”.

Every time I’m doing a new search, I have to go into the filter settings and click reset-