ithemes Security Won't Save changes

When I make changes to the iThemes Security (free version not Pro), it will not save. I click the Save button but nothing happens. I have cleared cache, exited, rebooted, re-entered site but nothing on the security plugin saves. I have this on several other sites and it is an intermittent problem, but this one just wont save.

I want to add the Brute Force ID API number (again, do this quarterly it seems). Only this time after I enter the number and click save, nothing happens. I tried other changes on the security plug in and they wont save either. Luckily this is just a test site for me.

https://www.nshm827.info

Thanks