Thanks @nataliemac, email sent.
Thanks @nlpro. Hosting company has said they can’t help any further. I’m planning on moving hosting anyway so hopefully the issue will get resolved that way.
I guess my next question is – how important is this loop back test? Will it really affect the security of the site?
Thanks again.
Thanks @nlpro. I forwarded this to my my hosting company and they’ve checked a few more things. They still think it’s something to do with the IP address. Any idea how I can get iTheme Security to check the IP address is whitelisted?