Steps to reproduce the issue:

1. Follow the steps as per the document: [Getting started with Red Hat Process Automation Manager -  Designing the case definition https://access.redhat.com/documentation/en-us/red_hat_process_automation_manager/7.10/html-single/getting_started_with_red_hat_process_automation_manager/index#case-management-designing-IT-hardware-proc;|https://access.redhat.com/documentation/en-us/red_hat_process_automation_manager/7.10/html-single/getting_started_with_red_hat_process_automation_manager/index]
2. Once the step 7 - Define the roles involved in the case - is performed and the change is saved (step 8), close the process, open it again and check the metadata attributes. It should contain one customCaseRoles: owner:1,manager:1,supplier:2;
3. Remove supplier from the Case Roles, save the change and then close the process and open it again;
4. Navigate to the Case Management and check roles - it will contain: owner, manger and supplier (although the supplier was deleted in the previous step).