advanced search is not working for character ő

[HonkXL]

I have a lot of persons with this place:

Hőgyész, Tolnau, Ungarn

When I enter this to birthplace in the advanced search, it is not found.
If I enter Högyesz (with ö instead of ő), then it says that there are too many hits. If I then add a birthdate of a really existing person, nothing was found.

The advanced search works for all cities with characters like é or á, but not for places with ő