That is indeed interesting. The results link is requested with the get_permalink( $id ) core functions, which always should return the correct URL, as WPML nicely appends a filter to it to make the appropriate modifications. My guess is, that for some reason this filter might be malfunctioning or removed during the caching process for ajax requests (?) and not changing the URL as it should.
I did some googling around and found that others have had similar issues with WPML, but the reason was never specified. Someone actually found a possible solution, which may work here as well. I've combined his solution with a filter, it's worth a try. Put this into the functions.php file in your active theme directory (copy from line 3):
Try removing your solution temporarily to see if this works. If so, then I recommend using this one instead, as this won't be removed after a plugin update. Let me know if this does anything at all.Best,
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