With a static public address, you have real issues. ( Likely you also have a domain name associated with that address)
First, WHY static address if no domain name or web services on your systems?
But back to the question: Usually, there's a means to disable remote management
My netgear states the enablement: Turn remote management ON { } so I cleared the box and restarted the router.
Attempting
http://wan-side-ip-address// just times out and adding the port :8080 does too.
If you can't stop that behavior, be sure to create a very strong password (and document it as it will be difficult to remember.
eg: create a sentence of at least 8 word and use the first letter of every word
Then make some of those characters UPPER case,
add a special character to the front (#$*@_+=)
and at least two digits at the end
If someone CAN access the config login page, at least they can't use a brute force cracker to get access