A role defines allowed actions, while access level helps determine which records the person can work with.
Settings > Roles & Permissions manages role definitions. Changing a role's permissions affects people assigned to that role, not just the profile you were viewing. Role eligibility also influences who can be selected as a Case Manager, staff manager, or investigator.
Full Access does not bypass permissions or access groups. Assignment to a case does not automatically reveal internal updates, files, or financial information. Resolve the specific missing permission or relationship rather than granting broad administrative access.