Within an assembly I drew a new part, I then copied that part (using the copy command). After that I added a couple of features (thru holes) to the original part. Said features appeared on the second copy as well, these features are unable to be deleted/surpressed without having the same affect on the original part where the features are desired. Creating an instance instead of using "copy" does not help. Localizing is not an option and externalizing does not help. Please advise if there is a way to delete/ surpress these features in the second copy, thanks for your time.

Cheers