Steps to replicate the issue (include links if applicable):

• In Luthor, when you select a specific lexeme containing a space, there is no result, see for instance https://luthor.toolforge.org/usage/lexeme?lid=L199477 or https://luthor.toolforge.org/usage/lexeme?lid=L185470 (while there is result on https://en.wikisource.org/w/index.php?search="all+at+once" )

I guess there is an encoding or string sanitizing problem somewhere.