Air freight capacity is greatly reduced due to a lack of passenger flights. There are passenger planes flying solely for freight, and even Airbus designed a system for securing cargo in passenger seat.

Sea freight has experienced a bit of a perfect storm. People looking to replace air freight due to the increased prices there, increase in orders due to everybody being stuck at home, UK businesses trying to stockpile before Brexit kicked in, backlogs at ports, and just general delays has driven demand well above capacity, along with prices.

I'm guessing it's going to be at least another couple months before things return to more normal.