I wandered into this interesting story on the FreightWaves.com site: Inside California’s colossal container-ship traffic jam.
It sounds like there's a two part problem: lots of cargo wants to arrive in the port, and onshore cargo processing is significantly slowed down by COVID impacts in Southern California.
In an alert to customers this week, carrier Hapag-Lloyd reported, “All terminals [at Los Angeles/Long Beach] continue to be congested due to the spike in import volumes and [this] is expected to last until February.
“Terminals are working with limited labor and split shifts,” it said, asserting that this is related to COVID. “This labor shortage affects all terminals’ TAT [turnaround time] for truckers, inter-terminal transfers and the number of daily appointments available for gate transactions and delays our vessel operations.”