Sure thing. Sorry, maybe I wasn't clear.
My tree on ancestry wasn't acquired from other members trees, but I put the tree together myself, using a written tree given to me. I wanted to compare that tree with sources and make sure there are no discrepancies between the handwritten tree and the public record. Also, I wanted to move the tree over to wikitree, so that it became available to anyone who was interested, and not stuck behind ancestry.com's pay wall. So I sourced it as much as I could, and found quite a few sources that were, thankfully, consistent with the handwritten tree. This was several month ago.
This week, when I went to create a gedcoms from the ancestry tree, the sources were all gone. Several people from the same family in Scotland are missing their sources. I find this very odd. I e-mailed ancestry.com, and have yet to hear back.
I strongly suspect that some of the responses to my question from other Wikitree members might be correct. There might have been some regulatory changes/contract updates between ancestry.com and other jurisdictions that meant that ancestry had to remove the sources in order to comply with these changes. I didn't think of that, but that seems like the most probable answer. Perhaps it has something to do with the recent European General Data Protection Regulations. I'm not sure yet.
It's really not that big of a deal, I was just curious. There doesn't seem to be much I can do about it. Thanks for your interest in my question.