I believe that Harper felt demotivated because she did not have an open communication relationship, that did not allow her to understand how his new bosses mindset is, so she could have been more proactive and show her job and understand how she could demonstrate it to his boss in order to have his recognition of her work and make her feel fulfilled at her work and delivery great results.

If I was the HR manager I would try to have more often feedbacks that she could have the chance to express her feelings about it and the boss would have a chance to understand her side, also would mention that everyone has different ways to work and express themselves. Would also give them a chance to express what each one side to be able to find a common ground that would work for both of them.

Losing Haper is not good for the new boss, even that they are on different levels in the company Harper has been there for a longer time and can be very helpful for the company. Also, having an employee that loves your work, feel motivated and that is dedicated can deliver better results that also impact positively David.