Only approx. 10 posts are harvested from the timeline?

If you are only able to harvest a few (10-15) posts for various target profiles, your harvesting profile could be the culprit.

Facebook has implemented a new blocking mechanism. The result is that only some posts are shown in a timeline. It makes it impossible to load more afterwards.

You can determine whether your harvesting profile is impacted by this mechanism by manually scrolling down the timeline. If, after a few posts, the webpage stops showing additional ones (see image), then you should go to the Profile Manager and switch to the primary profile.