As I wrote already, Human Authorization add-on is NOT involved in proceeding on the database side. It doesn't even read from database.
Yes this error is related on auto_increment field, but this only means mySQL is not able to create new auto_increment ID in your posts (or topics) table. If it has created it successfully before, and urgently stops to create, that only means the reason is somewhere in mySQL.
Your hosting support will always say "it's a software issue" like I already described here
. As as I wrote above, there is only one way to fix it. Change the hosting server, you won't never find a proper solution on the hosting team side if they are unqualified.
By the way, what is the highest post ID or topic ID in your table?
And when does exactly this error happen? When you post as a guest - post a message, or topic, or anything else? Please describe everything in steps else it sounds not clear.