I thought I remembered this same thing happening when I tested it a long time ago. I'm not positive as to how the code works, but I'd imagine this is what's happening. First, the two moves are linked together and count as one single move, acting on the same turn. Copycat does not look at the partial move that was just completed before it because it's looking for a full move to copy. However, Copycat, Assist, etc are hardcoded to not call full moves if they are linked together. This means that no matter how many times you use the combination of move+Copycat, Copycat will fail to call anything.
Hack_Guy Slayer95 How do you want to proceed?