Moderator, Iberia Airlines, Airport Lounges, and Ambassador, British Airways Executive Club
Join Date: Feb 2010
Programs: BA Lifetime Gold; Flying Blue Life Platinum; LH Sen.; Hilton Diamond; Kemal Kebabs Prized Customer
Posts: 63,945
This is a longstanding glitch. BA uses a set of standard codes for the taxes and a look up table. Though BA quickly updates the correct fees, it doesn't always correct the look up table which sometimes picks up an old table description. A data error if you like, but not one that adversely affects you in error.
In this specific case code LJ is "Sweden Aviation Tax (LJ)" which started on 3 April 2018 with a view to reducing emissions. It's similar to APD and goes from 60 SEK for domestic to 400 SEK.