https://www.bloomberg.com/news/articles/2021-01-18/why-the-cost-of-shipping-goods-from-china-is-suddenly-soaring
45 minute listen and pretty much definitive. No mention of Brexit unless I missed it.
this happens with every shipping sector, containers, dry bulk, tankers, as charter rates rise and fall. Shipping is cyclical. All that happens is they build loads more ships as rates rise and there is a correction as tonnage becomes oversupplied. And so it goes on.
On the flip side crude oil...