Cant fetch event category data

http://localhost:8080/index.php?module=API&method=Events.getCategory&idSite=6&period=range&date=2018-01-01,2018-01-31&segment=eventAction==PublicationReadingDuration&format=json&token_auth=9ee59c92cc717332a56d0fed157ac54c
Above URL is working fine - I’m using it to fetch list of events.

But when I want to get data for specify eventCategory, I’m getting empty array :confused:
http://localhost:8080/index.php?module=API&method=Events.getCategory&idSite=6&period=range&date=2018-01-01,2018-01-31&segment=eventAction==PublicationReadingDuration;eventCategory==industrikatalog-bog-nr-4-jop4tn&format=json&token_auth=9ee59c92cc717332a56d0fed157ac54c

And next magic for me is that for some other eventCategory the data is returning correctly
http://localhost:8080/index.php?module=API&method=Events.getCategory&idSite=6&period=range&date=2018-01-01,2018-01-31&segment=eventAction==PublicationReadingDuration;eventCategory==special-styrkerne-i43qh9&format=json&token_auth=9ee59c92cc717332a56d0fed157ac54c
http://prntscr.com/jep0cz

What’s wrong?
core:archive run and finish successful.

PS.
I’m using Matomo 3.3.0.