Probable circular dependency, but query still runs
There's nothing wrong with your model. Au contraire - it's pretty advanced!

employment_statuses provide data in a time-lined, historical, fashion, whilst departments identifies the actual manager.

These entities are very different both in purpose and use (queries on employment_statuses will serve different scenarios than those on manager).

I have to congratulate you, as I repeatedly work with peers that just can’t abstract this kind of scenario (the majority just see the now, or, at maximum, a single then - not the natural sequence of thens leading to the as today).

A remark: you should move high/low_salary from positions to another time-lined entity.