Do you have blocked account on Facebook?
I am aware that you have at least 300 groups on your account, but you need to visit them again personally and need to check their rules.
There are a lot of admins of that groups who forbid posting with autoposter.
That is the main reason of your blockade.
So go to your account and check every single group where you plan to post with auto poster. If it is not allowed then either go out either remove it from schedule on auto poster.