I started experiencing this issue a couple days ago.
As part of my workflow I open linked files from InDesign in Illustrator to impose for printing and laser cutting. The problem is when I copy/paste linked files, the files I paste show up larger than the file I'm copying from. The edges get cropped off the enlarged linked file, and then my die line doesn't line up anymore.
I suspect I've hit some sort of keyboard shortcut that's causing it, but I can't find anything in preferences that would affect the sizing of a linked file when pasting.
Any help is appreciated.