The bug doesn't happen when saving (the line correclty shows in the recently-used.xbel file), but when filtering the entries that populate the menu. If you comment the GtkRecentFilter in src/interface.cpp (lines 1020-1022), the UTF files show as expected (well, other files unrelated to Inkscape too, that's why there is a filter...).
Investigations in progress.
The bug doesn't happen when saving (the line correclty shows in the recently-used.xbel file), but when filtering the entries that populate the menu. If you comment the GtkRecentFilter in src/interface.cpp (lines 1020-1022), the UTF files show as expected (well, other files unrelated to Inkscape too, that's why there is a filter...).
Investigations in progress.