If the outbound segments have been reissued (new ticket No.) they will no longer be visible in the same eticket receipt as the inbound flights. There will be/should be a separate receipt for the reissued segments. If you see the ticket No's in the reservation it is all fine, and you shouldn't be concerned about the lack of receipt.
You wait until check-in opens. If you are able to do OLCI all is fine. If you are not able to do OLCI, you call LH as there might be an issue with the ticket/no ticket.