The following is from P&O
Please note there will be no sailing @ 16:30 ex Larne or 20:00 ex Cairnryan today. All other services are operating as scheduled.”
Additionally Stena Superfast VII is off today for some maintenance, so just 1 ship for each Stena and P&O running today. It would appear that this is another technical issue for European Causeway. No indication how long she will be off service for yet.