

Uhh, this might be true for WebRTC, except not much uses WebRTC other than for realtime streaming/calling. Jellyfin for example is just an mp4 stream over http; and http(s) will only use the IP in the DNS record. I’d like to see a packet capture if you are certain something is switching IP.
Cert pinning is pretty uncommon in the self hosting community though, especially when both Cloudflare and Let’s Encrypt have a 90 day validity period and often renews after 60 days.