I am having the same issue. I have done some testing and agree that this is related to the spyglass building being placed. To get the masonry building working again, I have had to remove the spyglass buildings, then build a new masonry building. Any buildings previously placed still will not upgrade to stone. They need to be removed and placed again for the conversion to stone to work.
I am having the same issue. I have done some testing and agree that this is related to the spyglass building being placed. To get the masonry building working again, I have had to remove the spyglass buildings, then build a new masonry building. Any buildings previously placed still will not upgrade to stone. They need to be removed and placed again for the conversion to stone to work.