We have observed that when we edit one of the linestyle (original and copy), if it happens to be the original linestyle it messes up all the drawings that already has that in use. Ideally after the duplicate is made and we rename to customize it further, the existing drawings shouldn't be impacted since the drawings pull the linestyle based on the name. But it seems if you pick the original copy instead of the duplicate copy, it ruins the existing drawings. please test it and if you are impacted the same way, introduce the duplicate copy names auto generate as Copy_name or name_Copy as default, so that the users will only modify the duplicate.