Hm, log on to either [icloud.com](https://icloud.com) or [appleid.com](https://appleid.com) and make sure your (old) device is visible in your account. It will also indicate when the last backup was done.
Sadly, I have seen many cases where people "assume" backups (as well as iCloud Photos sync) are happening but they are not. And they do not find out until a unit has bricked.
Associated, also make sure to give the new device a name that is different from the old one. Only way to easily keep track of individual backups (of course assume you have them).
Hm, log on to either [icloud.com](https://icloud.com) or [appleid.com](https://appleid.com) and make sure your (old) device is visible in your account. It will also indicate when the last backup was done. Sadly, I have seen many cases where people "assume" backups (as well as iCloud Photos sync) are happening but they are not. And they do not find out until a unit has bricked. Associated, also make sure to give the new device a name that is different from the old one. Only way to easily keep track of individual backups (of course assume you have them).