wordpress - get_post_meta not working in different language -

i have code: $variable = get_post_meta($post->id, '_fcs_hp_spsite', true);

i using polylang plugin. suomi language works perfect (it returns post id). on english language, doesn't return nothing (even post there sure). worked before , stopped (i think after irelevant text change in 1 of posts).

after research, believe there's "synchronization of custom fields" setting on plugin settings. make sure have checked.