Yes, looks to be a combination of things.
Article from Irish Times from Monday:
Expect overseas Christmas mail throughout January, says An Post
Parcels from overseas could land this month as companies try to clear Covid-19 backlogs
People have been told they can expect to be receiving Christmas cards and presents from friends and family overseas throughout January while festive mail sent abroad is facing similar delays as delivery companies worldwide work to clear Covid-19 related backlogs.
An Post has warned that restrictions caused by the pandemic as well as local lockdowns across the world are still having an impact on the distribution and delivery of international parcels and letters.
It said the number of international flights continues to be severely impacted by the crisis, with only limited space available for international letters and parcels.
As a result, many items posted in Ireland during December for delivery across the world are still in transit through airports and sea ports while local delivery depots across the globe have been impacted by Covid with some areas are also dealing with severe winter weather conditions.
In a statement An Post said it expected to be receiving incoming international Christmas parcels and letters for delivery in Ireland throughout January. “We assure customers that we continue to deliver all international letters and parcels as soon as they are received into Ireland,” a spokeswoman said.
Brexit is also causing a headache for delivery companies with the addition of significant volumes of red tape and form filling as a result of the UK’s departure from the EU at the start of the year.
DPD said last week it has paused deliveries from the Britain to Ireland as a result of Brexit logjams. An Post has expressed confidence that it will be able to overcome Brexit hurdles as it works to deliver as many as 16 million parcels into Ireland this year.