Can't upgrade base

Pre-Update 33 I was able to build in sandstone and then upgrade to stonebrick or wood by simply putting the new over the old. I can’t anymore. It tells me when trying to upgrade a foundation that the space is occupied, or building here will block your spawn point. I was able to replace a few pieces after tearing one out to start with, but now I have a hole in my base that I can’t fill back in.