AP scores changed?!?!

Sorry, I’m not sure if this is the right place to put this. Anyway, last year a friend of mine took the AP world history exam and when she checked her score last year she got a 1. When she checked her ap scores again this year she said that her score changed to a 2 somehow!!! Another friend took the APUSH exam this year and when he checked his score he gota 3 but when he checked later in the summer his score changed to a 2. Did the college board change they’re scores? And if they did then why? Is it common that the scores change?I ddon’t think it’s likely that they both read their scores wrong the first time…