Customer created domain on NG web hosting based on shared IP address and created WWW DNS record. It is expected that both domain.tld and www.domain.tld will use single SSL certificate, but it only works for domain.tld and does not work for www. Default certificate is loaded when one browses www.domain.tld
POA-87454: Server Name Indication (SNI) feature for NG does not work for www prefix.
The issue has been fixed in OA 5.5 update 8. Please make sure that your environmant has OA 5.5 update 8 or higher.