Originally Posted by
llunow
Asking one of the immigration agents once I was forwrded to manual check, he told that it is a known issue with Danish passports which only have a success rate of 50%. He couldn't say anything about the cause though, since no clear pattern could be seen.
I had about the same success rate with my (other, non-Danish) EU passport (back when I still traveled to the UK by air). So maybe it's more a machine than a passport problem...