You never know if these subtle differences were intentional to begin with. It might have been the same once upon a time, but then during an emergency outage someone makes a quick fix in one place but forgets to update all other copies of this code.

Repeating what others already mentioned, often it can be the same thing but written in a slightly different way. Even basic stuff like string formatting vs string concatenation can make it non-obvious that two pieces of code are copies.