Instagram Import: only 20 Posts

Hi,
When i am trying to import my Images from Instagram (nearly 1500 Posts) the Batch Import always stops after the newest 20 Posts. I already tried the proposed solution from this thread https://www.ads-software.com/support/topic/instagram-only-import-last-20-posts/
But deleting all imported Posts and emptying the Trash didn’t work.

Could it be something with the Instagram-App? e.g. not enough Permissions?

Thanks for your help!
Heiko