BidSlammer failed to place the bid I had set up for item 204816024733. This is not the first time this has happened.

Hello John,
Thank you for your question about this item. You added this bid less than a minute to closing. You must add the bid 2 minutes or more before closing.
I'll check to see why the system didn't catch this as it usually does, but in any case, the bid would not have been able to be entered.
I hope this has been explained to your satisfaction. I'm happy to help with any other questions you may have.