This is about private security provision.
Harry already has and pays for it. He wanted public security provision (i.e. the Met), paid for by the taxpayer whilst in the UK. The main reason for this is reportedly not about the money, but because police protection has much greater powers/effectiveness- they can close off roads/provide blue light escort, carry firearms, powers of arrest etc. And, most importantly, have access to all of the state’s machinery for intelligence and threat assessment.
The article refers to King Charles paying for private security guards for Andrew, as his public security provision is being withdrawn.
They are both being treated the same as in as non-working royals they aren’t ordinarily permitted routine police protection. The only difference is that Harry is funding his own private protection (as he has an income to do so), where as Charles reportedly may be funding Andrew’s, because he has no income of his own.