The story started here, when I dismasted:
https://www.youtube.com/watch?v=IgGG0U3SEZo
At 1:17 you can see how the daggerboard was pulled from the security line that I attach to the shroud with a carabiner. (Lesson learned: now it's a bungee).
I didn't realize that the daggerboard had made a crack inside the hull, so after repairing all the rest I tested the boat yesterday, with the following results:
https://www.youtube.com/watch?v=kTs__BRPUMc
Fortunately it's easy to repair.