Just can you change the error in your code, please
add_filter('acf/fields/post_oject/query/name=YOUR-FIELD_NAME', 'YOUR_FUNCTION_NAME', 10, 3);
to
add_filter('acf/fields/post_object/query/name=YOUR-FIELD_NAME', 'YOUR_FUNCTION_NAME', 10, 3);
post_object
Issue resolved. Thank you!
I saw those topics, but if to be honest I don’t understand what exactly I need to do, can you help me?