Greetings!
Thank you for the good luck! Since we reworked the building system there’s a high chance that the work done by now will fix it. However, since you’re experiencing the issue on Singleplayer, we can’t completely rule out that something might be happening to your saved file.
If you have the Testlive product installed you’ll be able to test your saved file once we release the update there.
Let’s hope for the best, and if the issue still persists in Testlive make sure to poke me and we can request a new investigation. 