Ports in the US
were affected. They had lockdowns and port activity did stop AFAIK.
When things got better - they opened up the ports and a container logjam started (Long beach is closest to me which I can report on).
Things got really bad, Long Beach Longshoremen are now working around the clock , three shifts a day to clear up the Logjam. Like brother
@MH.Yang commented, space for storage of containers is limited, which compounds the problem further. You can only stock up containers so high for safety, straddle carriers and container stackers cannot work beyond a certain height.