Sort order in tag "Genre"

I have moved my LMS 9.7.1 from a PC with Ubuntu 14.04 to a PC with Ubuntu 16.04. So far no problems but ...

The sort order in the Genre-tag has changed. Within the Genre tag I use (besides the "normal" genres like Country, Classical, Folk, Pop etc) special genres beginning with a special leading sign ( _ = U+02CD; Dec 717).

Under Ubuntu 14.04 the sort order in the Genre tag was: first the values with the special leading sign, then the normal values
_Buehnenmusik
_Kammermusik
.
.
.
Blues
Country
Classical
.
.
.

Under Ubuntu 16.04 the sort order in the Genre tag is: the values with the special leading sign and the normal values are mixed
Blues
_Buehnenmusik
Country
Classical
_Kammermusik
.
.
.

Since I use the special leading sign to separate "normal" from "special" Genre values in a sorted Genre list I don't want to live with this "mixed" Genre list.

Has anybody an idea why the sorting behavior in the Genre list has changed and how I can return to the pld sort order?

Regards Rainer