Question about Samsung Galaxy Smart Tag2

I have no experience with shipping containers, but your tags can only be localised if they are detected by a mobile via Bluetooth. The metal container housing and the goods in the container will have an additional shielding effect. In addition, a person with a mobile phone must be in the vicinity of your tag, which makes the whole thing even less likely.

Hello, these things work via Bluetooth. This has a limited range of around 20 metres. Whenever someone with a smartphone with Bluetooth switched on comes within this radius, the passer-by's mobile phone sends the position of their mobile phone to a server without their knowledge or intervention. From there you then receive the information about where your tag is located. On a ship in a container, it is very unlikely that someone with a mobile will come within the 20m radius of the tag. In addition, cargo ships often sail outside the network coverage of a mobile network, which means that a passer-by's mobile cannot transmit the coordination to your server. Another complicating factor is that a metal container blocks radio waves, which unfortunately also applies to Bluetooth. This means that you will only get a signal again when someone with a mobile in their pocket with BT switched on opens the container.
I hope I have been able to explain how it works.
Have fun with it!