I tried to book avios' tickets on a couple of different Finnair flights. The website shows availability but when I click on "continue" I get the error message "Sorry, there’s a problem with booking this journey online. You can try selecting other flights or contact us so an agent can help you book the flights you have selected".

I haven't called yet as FTers are often better informed than agents. Has anyone experienced this? Is this a "phantom availability" issue or should I get the seats easily if I call?