Alexandersson ran wrong - and failed to repair the mistake.
When all orienteers finished, the Swede was sixth.
- I have been in a forbidden area so I may also be washed so there is not much more to say, Alexandersson continues.
The championship's first gold came in the relay on Sunday, the second in the knockout sprint on Tuesday - but there was no third, in the sprint.
Britain's Megan Carter Davies won, Simona Aebersold from Switzerland came second and Alice Leake from Great Britain came third.
Alexandersson already has fifteen World Cup golds in orienteering, one of which is in individual sprint (from 2021).
Last year, the Swede won five gold medals during the world championships, in sprint, sprint relay, middle distance, relay and long distance.
In total, she now has 28 World Cup medals in orienteering.
The text is updated.