Without warning this just started happening to my files. XD is going mental. At the same time I suddenly couldn't save anything on the file I already had open before this started happening ("The document ..... could not be saved").
Are you seeing this on Mac or Windows 10? Did this start happening immediately after you upgraded to the January release, or did anything else happen (e.g. OS upgrade)? Does this happen on a new document? Also, do you happen to have a dual monitor situation?
This is happening on MacOS Sierra 10.12.3. I have older XD files created on a different license than the new one I'm using now, however everything was going fine until a few days ago. I did no updates that could have messed with it.
It happens on new and old documents. I do not have a dual monitor situation.