I don't think it's related, because the lot I built didn't completely disappear, it just reverted back to the original Vlad's mansion in the game as if I had never bulldozed it and built anything new. Same thing now when the issue came back, the build was still there but it is as if it didnt save the build, but it did save the gameplay. Any new relationships and so on are there and are saved, but the lot next to the one I was playing had turned into an older version of it, so it was a half-built version Ibhad saved previously but not the finished build.