Thanks but the firewall settings are not changed.
Also the 403 error occurs if I try to add an additional blocked IP address (which is not mine). It allowed me to add IP addresses in the past and I have probably 40+ listed but when I tried to block a new IP address it gives me the 403 error and locks up the entire site.
The same issue occurred when attempting to block brute force attempts.
So for now I have just stopped try to add to the blacklist addresses