Black eyed susan problem
Hello. Thanks for your question and the photos. The damage on the leaves appears to be caused by slugs or snails. If you don't have slugs or snails on other neighboring plants, it is possible they came in with the Blackeyed Susan plants.
There are several things you can do. First, look for and eliminate all slugs or snails you encounter. (You can slice them with a pruner.) Know what slug eggs look like (a small round gelatin capsule) and destroy them if you come across them when digging. Remove all dead, dying vegetative material on the ground which can harbor slugs and snails. Water in the morning, rather than the evening.
Oregon State University Extension has a handout that covers the wide range of things that you can do to eliminate snails and slugs. You can see it at this link.
Best of luck.