Why is ICANN sending my site so much traffic?

For many months now, ICANN has been sending an absurd amount of traffic to a site I maintain from 192.0.32.224 and 192.0.47.224. From those two IP addresses, we have received 12,206,044 requests in June 2022 alone. In the last 6 months, the rate seems to remain relatively constant. It adds up to about 40GB/month.

Each entry is this: GET / HTTP/1.1" 200 4294 "-" "Mozilla/5.0 (ICANN IT Operations +1-310-301-5800)

Why do they request this page so often? I wrote to their "ops@icann.org" address several days ago but haven't heard back. I know I could block them with a firewall but mostly I am curious as to why this happens.