i checked the buddypress-pt_BR.po/mo. Sitewide Activity is correctly translated.
I also added all gettext filters to the po, as mentionned by @shanebp
without any result.
I also tested with mesocolumn theme and magazine theme, with no result.
The only solution for the moment is to change the original code to the old style way of translating a string ( __(”,”) )
the string is in bp-activity-loader.php:109
Change
‘directory_title’ => _x( ‘Sitewide Activity’, ‘component directory title’, ‘buddypress’ ),
to
‘directory_title’ => __( ‘Sitewide Activity’, ‘buddypress’ ),
will resolve the problem.
