eBay US turning back shipments to Australia

I buy a not insignificant amount of stuff from eBay, surprising nobody here. I owe much of my retrocomputer hobby to Japanese second-hand good stores, my father in law, and online auction sites. Much of this comes from Europe, but I do buy the odd item from the United States as well. Sellers in certain countries like the US and UK can opt into eBay’s Global Shipping Programme. This allows sellers to list their items as available for purchase from overseas. These sellers send their items to a domestic distribution centre, which performs the requisite work to ship the item overseas on their behalf. Sellers get access to a global market, and buyers like me get to buy from someone in rural Montana who otherwise would not have considered Australia a viable destination for their goods. It’s great. The Global Shipping Programme continues to work a treat for stuff I’ve bought from the UK, and my items from Europe have had no issues. But for whatever reason, the US side seems horribly broken…