Have you enabled offline finding on Smartthings Find on your phone and your kids’ phones?

Using the cellular network takes much more battery (especially when the signal is low and if you are using 5G) than using Wi-Fi only.

The prices for phones are a little cheaper in Korea than in Europe, but I don’t really recommend buying a Z Flip in Korea if you live in Italy.

You can buy the unlocked version in Korea if you want to, but usually offline stores in Korea don’t offer much discount compared to online stores and even buying online doesn’t really help unless there are some good discount deals. Since you are a foreign tourist, finding a good deal in Korean online shops would be very difficult and even if you somehow managed to find it, you won’t have a chance since you don’t have a Korean credit card.

In addition, unlike Apple, Samsung phones that are released in different regions vary to some extent regarding the support for network bandwidths as well. The firmwares differ too, so you might run into some unexpected problems while using the Korean unlocked version in Italy.