iThemes Banned Users not saving

Just noticed on several sites that Banned Users is not saving. Double-checked after getting the changes-successful green message — but when I went back to banned users, the check box was no longer checked although the list was there.

I came to spot this because I noticed a banned IP was still trying to access no-existent files. So far I have seen the same thing on two other sites that I just rechecked. This is worrying because I am guessing the same thing is happening on the other sites I haven’t checked yet.

I’ve got the latest version and this is the first time I’ve noticed that the green success-after-saving is fact false. It may well have happened any number of times before because I do not go back to banned users to make sure. I just trust the iThemes success message.