This happened to me last year. Bought a cs4 and cs5 design suites back when they came out. Only ever used on one computer. When i unauthorized my computer and moved it to a new one they wouldn’t authorize it and demanded proof of purchase. I showed those fuckers a paper receipt from 10-15 years ago. They wouldn’t accept it and required additional information to verify i was authorized to purchase the software at the discounted price from an authorized retailer. It took several back and forth before they issued a new cd key instead of reactivating mine.
I suspect the cdkeys were cracked at some point and i just had the unfortunate luck of mine being abused. Would be nice if they didn’t require online authentication for a product i legitimately own though. If they are going to require online authentication then they need a more secure way of generating their cd keys.