In the latest update in this thread, Zero tells us:
Just so everyone knows, in tomorrow’s patch, we’re addressing the problem with the placement of objects that is causing them to be sunken.
At this point, we’ll have addressed all the major issues that we know of.
If you’ve got something going on that’s new, and that we haven’t yet mentioned, please let us know in this thread. And please provide details, like the project ID and name and general location and how to reproduce the bug.
Also, EP Dan Stahl had this to say:
After the Season 6 launch, it has been all hands on deck for the Foundry, which should be turned on for editing this week if all goes well.