I had the same problem and also noticed an enormous amount of backslashes added to the blacklist user agent field. I cannot delete them. If I activate the feature, the htacess file is not formatted correctly because of this and the site is unreachable.
I am unable to erase the information in the field. I’m trying to locate it in my database but cannot. In EXCEL it resides in a cell that contains an unusual number of characters, which is preceded by aiowps_banned_user_agents. Is this a buffer overflow attempt?