I have been asked to review a document but I have a dilemma: in below phrase should “D” be capital?

Why can’t people collaborate within the Department?

The Chairperson of

Department is responsible for….” “You should focus to

support our Research Chairs” These sentences are from

a formal proposal and I believe that non of the words should have the first letter capitalized.

What is wrong with the first letter of the job title, with the words: department, chairman and chairman all over the document? Should caps be capitalized?