All domains show the default server page.
Two or more IP addresses are configured. All domains are configured to the external IP address. However, all requests come to the internal IP address.
--- packet capture
14:38:46.062753 IP 18.104.22.168.50041 > 10.0.0.137.http: Flags [P.], seq 899:1204, ack 2944, win 63004, length 305
14:38:46.063981 IP 10.0.0.137.http > 22.214.171.124.50041: Flags [P.], seq 2944:4376, ack 1204, win 18760, length 1432
Incorrect IP address configuration.
Plesk is behind NAT: Change the shared IP address to internal and configure DNS templates according to the article KB #1984 .
Plesk on the external (white) IP address: Give direct access to the external IP address (TCP port 80) and configure this IP address for all domains.