Game mode: [Online | Singleplayer]
Problem: [Crash | Bug | Performance | Misc]
After hours of testing and building I have found that stability on building parts can change after logging out and back in. This seems to be the reason parts are destroyed at log in. I have witnessed pillars at 100 percent change to 20 percent. I have also witnessed parts placed directly on a pillar in the ground give a 20 percent reading when an identical part next to it gives a 100 percent reading. The if I destroy the 20 percent pillar and replace it goes back up to 100 percent. Larger buildings seem to be more susceptible perhaps will many parts involved the game has more problems remembering although I have seen these issues on smaller buildings just not as bad.
Steps on how to reproduce issue: