I've also run into this issue I'm the latest update. I would give it 3 or so minutes but it never finishes building ships. I noticed that it was possible to exit to the main menu and then continue the campaign from there. This let me get back to playing however I'm now wondering if it broke the campaign. It's not clear if I'm at East with Italy (relations -100, right panel has at was 0 vp both sides, but Italy isn't in the left panel and I don't get missions against them). Germany and Austro hungry have requested piece, I hit yes but there is no peace or war continues pop up. I'm going to start yet another new campaign and time the turn ends (no skipping work around). I've noticed CPU usage is very low during build, I can't imagine it actually takes 3+minutes to build ships given that I'm running an overcooked 3600x.