[teejmya]

Since it hasn't been mentioned, my first thought is valid users browsing on iOS with iCloud Private Relay enabled.

https://support.apple.com/en-us/102602

I have this enabled on my iPhone and websites that report my IP show the block is owned by Cloudflare or Akamai.

[teejmya]

Found the list! It might be worth checking if your suspect traffic is from any of these subnets: https://mask-api.icloud.com/egress-ip-ranges.csv