I've been in contact with the Finale support, and one of them happened to have the same Kontakt Factory library, so they were able to confirm the issue. If the Flute staff is set to solo mode the issue doesn't occur. I was asked to change the keyswitch to Staccato instead of Sustain to see if that would make a difference. It did. With Staccato on the Flute staff the issue doesn't occur. I've let them know this too.
Yesterday Finale support wrote:Are you finding that the Staccato key switch is providing you with the result that you need?
Today I wrote:No. Since I want a legato feeling I need to use the sustain option, which is the one that produces the swung notes. I thought that you and your fellow team member were going to do some troubleshooting?
We'll see what their answer will be. However, very often I get the feeling that the Finale support team seems quite lazy and reluctant when it comes to solve issues that doesn't strictly include a quote from the user manual, or references to it. I find it extra curious in a matter like this, since one of them is having exactly the same issue. He if anyone should be interested in solving it.
Does someone here have a solution this swung notes issue?