When we go into a client's account, and under the "Cost" panel, we try to "Assign Products" it attempts to assign products from our business account not our client's account. I am assuming we need to assign products to each account once they are setup, correct?
Thank you for posting. If you're on your client's profile page, you should only be seeing the products that are associated with their account. I'd recommend reaching out to Pro Support for help with this issue.