Unseemly political rows are nothing new for us, but the start of the Northern Ireland Protocol on New Year's Eve has also ushered in delayed consumer deliveries and empty supermarket shelves.
It seems Brexit hasn't gotten off to a good start for us. Marks & Spencer has suspended deliveries of nearly 400 items here while it figures out the new regime. And its much-loved Percy Pig fruit chew could become a totem of the complexities of the trade deal between the UK and EU.
Chief executive Steve Rowe has said it may not be able to send the item to EU countries like the Republic without incurring tariffs, as M&S itself brings the sweets in from Germany.
On its supply issues here, the company said that "following the UK's recent departure from the EU, we are transitioning to new processes and we're working closely with our partners and suppliers to ensure customers can continue to enjoy a great range of products".
The Northern Ireland Protocol, part of the Brexit Withdrawal Agreement, means Northern Ireland is treated as part of the EU single market and goods coming from Great Britain into Northern Ireland ports are subject to regulatory checks and customs.
Much of the paperwork is, in theory, to be carried out in the ports in Great Britain. But some companies in Great Britain had failed to get the message about what was required, according to Seamus Leheny of Logistics UK.
He told the Northern Ireland Affairs Committee this week that one haulier had to reject 15 loads of food set for Northern Ireland on the basis that the paperwork wasn't done.
There have also been delays in the shipping of supermarket products here. A large Tesco in Belfast was lacking in own brand Tesco Finest ready meals, dog treats and continental cheeses. Delays are down to the new protocol.
A spokeswoman for Tesco said it had a "good supply" coming in. "There has been a short delay on certain products, but we're working with suppliers to get these back on the shelves as quickly as possible and direct customers to alternatives where we can."
It's a truth (almost) universally acknowledged that the checks in Northern Ireland ports amount to an Irish Sea border. But the Northern Ireland Secretary of State, Brandon Lewis, asserts that the changes, while causing disruption, are simply building on existing sanitary and phytosanitary checks on livestock, which have already been in place "since about the 19th century".
Border control posts are staffed by officials of the Department of Agriculture, Environment and Rural Affairs. The Daera Minister is Edwin Poots, a DUP man whose party championed Brexit.
Mr Poots was criticised when he used Twitter to thank Brexit campaigner and donor Arron Banks "for everything you done" to secure Brexit.
While DUP First Minister Arlene Foster has said she will work to mitigate the worst effects of the protocol, her party colleague Ian Paisley has called for it to be dumped as an "unmitigated disaster".
That prompted SDLP MLA Claire Hanna to call him a "professional troll". He accused her of "nothing more than name-calling".
A routine row, but what's not routine is for consumers to be hit as hard as they have been this week.
A key Brexit rallying cry was that it would enable the UK to "take back control". Consumers in Northern Ireland aren't really in control at the moment.
Dunelm, John Lewis, Peloton, Made.com, AO.com, Amazon and Debenhams are among the big names who have paused their deliveries while they get their heads around the new situation. HMRC guidance which introduced a grace period on parcels simply arrived too late for firms.
A small leather goods trader in Co Down says he's been hit by a four-fold increase in the cost to ship supplies from the north of England, from around £16.20 to up to £90 per parcel.
"Some other suppliers from whom I get threads, dyes and hardware will no longer supply me in Northern Ireland as there is too much paperwork and uncertainty about customs duties et cetera. I have used a certain supplier in the USA, but only rarely. It is now cheaper to buy much of what I need or use from the USA rather than supporting GB/UK businesses."
Dan Wilson, author and online retail expert, said retailers in Great Britain will be weighing up whether Northern Ireland is worth the hassle.
"Couriers, such as Hermes and DPD, are already considering whether it's a market worth serving and many big brands use them for both for delivery and returns," he said.
"Royal Mail is obliged to continue to deliver all parcels under the Universal Service guarantee, but it is expensive, so we will likely see some retailers apply a Northern Ireland delivery premium on shoppers.
"Others will stop shipping to Northern Ireland altogether. We'll see (Except Northern Ireland) on more UK shopping websites in 2021 for sure."
Irwin Armstrong, the managing director of medical testing company Ciga Healthcare, was one of the few businesspeople here to publicly support Brexit.
The former Northern Ireland Conservative Party chairman said he remained a strong supporter of Brexit. He said that while there were "downsides" to the protocol "it actually gives us major opportunities with access to the EU and access to Great Britain".
"If our politicians ever get away from Covid and start concentrating on the economy, there's a lot of work they can actually do to promote Northern Ireland as a place to do business."
Asked if Brexit supporters in Northern Ireland can be forgiven for feeling hard done by as they witness shortages on shelves, he said: "Business exists to solve problems and successful businesses solve problems... Give it a week or two when everybody has learnt all the rules and done everything they are supposed to do, then I don't think you will see any difference on the shelves. There will be all the foodstuff we are used to back on the shelves."
He said problems were down more to the backlog of lorries at Dover before Christmas, when lorry drivers from the UK were blocked from entering France due to the emergence of new strains of Covid-19.
"I would forecast, by February 1, there will be minimal effects on anybody's life in Northern Ireland."
Speaking to the Ulster Business podcast, Seamus Leheny emphasised that the protocol is a live document and that further derogations and mitigations can be discussed with the EU and UK Government.
"It's in the EU's interests to make it work, because if there's resentment here publicly and business-wise towards the protocol, then that doesn't bode well for it in the long term," he said.
Margaret Canning is the Belfast Telegraph's business editor. Additional reporting by Ralph Hewitt