I am calling this out as a bug? If the role is a sales role, and there are no employee restrictions. Why can a Sales Rep not see ALL customers?

There is another setting under Sales Preferences which can prevent sales reps from seeing customers assigned to other sales reps.

@Nicholas LaHara it is also set to unrestricted... it's so weird

Is there a common theme among those customers they can't see?

@Nicholas LaHara duh, subsidiary. My user was in a parent and customers were in a child, so I wasn't validating the user-experience. Thanks.