In my forum software section, all of the other forum feeds are fine such as xenforo, ipb, mybb, phpbb, but vbulletin's feeds keep getting spammed. I have tried deleting it and adding it again, but still no luck. Is this a problem within xenforo or vbulletin's feeds? How can I resolve this?
The feeder should insert a record into xf_feed_log in the database for each thread that is posted from the feed. If you remove the records then it will allow for double posts. Make sure xf_feed_log contains records from that vB feed.