Yes, I understand that, but since no fix was related to desyncs, I decided to make the bug report anyway.
If you need any more information, I'll be around.

Another thing that seems relevant to me:

It happens exactly when I click a blueprint inside a book. And when I join back, the blueprint is still in my "mouse", being held.

Game desyncs && crashes when moving blueprints in a blueprint book around. I was changing blueprint's slots. At first I thought the issue had to do with changing the first slot which is the one that you'd see in the book cover. Then after some tests, it happened pseudo-randomly when changing...