PIP and working

HI, I am rather confused about conflicting information I've seen around the requirement to declare when starting a paid job if already in receipt of PIP.

On the B&W site it says "Work doesn’t affect personal independence payment (PIP) in so far as PIP is not means-tested and you can be paid PIP whether you are working full-time, part-time or not at all. So, you could work as a merchant banker earning millions and still be eligible for PIP.
However, you do need to be aware that work can affect the points you score in your PIP assessment and thus whether you are eligible for an award and at what rate."

However, on the Citizens Advice Bureau site it states:
Changes you don't have to report
You don't have to tell the DWP if:
you get a job, return to work or leave work

So which is correct? Any clarification on this would be most welcome. Thanks.