Elegran
But, Stoneof Destiny , Andrew IS a prince, and was born one automatically without any investiture, by virtue of being the son of the heir to the throne. His dukedom was deliberately given to him and legalised, and that could be reversed by the appropriate legislation, but there is no legislation to remove a title which was not specifically granted.
After his sex scandal abdication, George 111 was not allowed his original birth title "Prince George" , demoted to Duke of Windsor. He was allowed to keep HRH. But the Duchess of Windsor was not allowed an HRH.
Harry, Meghan and Andrew have "agreed" not to use HRH.. But Harry and Andrew must be well aware the Monarch can smoothly and permanently cut off use of HRH by royal prerogative, as happened to Diana.
Losing "Prince" is not impossible, has been done before.
<https://commonslibrary.parliament.uk/research-briefings/cbp-10370/>
"The title of Prince or Princess can be removed by statute or under the prerogative".