Graph API error #200 even with correct permissions

I’m setting up a bot to auto-post on a facebook page. But when i run the script, the graph API throws the following error:

Graph returned an error: (#200) Requires either publish_to_groups permission and app being installed in the group, or manage_pages and publish_pages as an admin with sufficient administrative permission

but in the app’s permissions, both manage_pages and publish_pages are marked as allowed, as well as the user (who is also the owner of the page) is setup as app admin.

i know this is (or, at least, was) a know issue but i’ve found no answer whatsoever.

is there any way to solve/work arround it?