HTTP/3 enable/disable handling can conflict with HTTP/2 handling when both form fields are submitted: each block reads the current protocol list before saving its own change, so changing both options in one submit can cause the later HTTP/3 save to overwrite the earlier HTTP/2 save based on stale state. Suggested fix: Parse both http2 and http3 inputs into a single protocol list and call save_domain_http_protocols once, or re-read the protocol list after the HTTP/2 save before applying the HTTP/3 change.