This video shows the issue. After restarting the computer and Traktor everything worked fine, but I wonder what could have caused the issue. The track in question was not being used/opened by other programs.
I'm quite sure that's a bug, and one that NI fixed a while ago. I haven't had that issue in years
Your version of Traktor is 6 years old. Traktor 3, a major version upgrade, was released in 2018. I would recommend upgrading--3 is a huge improvement
I wouldn't even want to file a bug report on it because that's just less developer time that can be spent on making cool new stuff, if they even support that anymore
And if you must stay on 2, do a minor version update. I was on 2.6.8 for a long time, not sure if that's the latest minor release of 2 but I can vouch for it being solid