When customers are added to "request participants" field one by one they receive an email and are able to access the issue but when the customers are added as a single organization to the field organizations they still receive the email but when visiting the issue they get No Access You do not have permission to view this request.
I think there might be a couple things to check
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.