Missing data security policies on custom roles

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In one of our environments, we have found a large number of our custom roles have lost all their data security policies. It is not all custom roles and seems to be primarily finance related roles with the problem. 

The custom roles were created from a seeded role using the 'Copy Role' function. It is believed the roles initially had the data security polices as expected because two other environments were cloned from the first environment and the custom roles in those environments are not affected.

If a new custom role is created by copying a seeded role, the data security policies are present.