Why it shows iPhone 13 Pro Max (4)

I have recently upgraded my phone from iPhone 13 Pro Max to iPhone 15 Pro Max. However, I noticed that in the Find My Phone feature, my new phone is labeled as iPhone Pro Max (4) instead of iPhone 15 Pro Max. I am wondering what could be the reason behind this issue and if there is a way to fix it. I also wonder if I made any mistakes during the data transfer process.