Are the IP adresses listed at .well-known/ipv4.txt correct?

I can't seem to allow traffic to our (IP-restricted) site. I've added the IP adresses from `https://securityheaders.com/.well-known/ipv4.txt` to a list of allowed IPs, but I keep getting 403s.

(Other IPs for other tools work fine, so the setup seems to be working OK, just not traffic from securityheaders)