A lot of relays are behind cloudflare or use other reverse software that protects the server by rejecting connections such as VPNs and Tor among other things. nostr:npub16r0tl8a39hhcrapa03559xahsjqj4s0y6t2n5gpdk64v06jtgekqdkz5pl once shared this which explains how to update Cloudflare. (Forked to show updated UI)

https://github.com/sudocarlos/on-cloudflare