Dual Sim

I think if you use smartswitch that it will maintain the connection 

Hello @GalaxyMac,

Hope you enjoy your new S26 Ultra!

Here are some tips to keep your work‑ and personal‑SIM assignments when you move your contacts:

1. Use Smart Switch - This is the simplest way to migrate everything, including the SIM‑slot information that is stored with each contact.
  On both phones, open Smart Switch (you’ll find it in the Settings or the Apps drawer).
   * Choose Send data on the S25 Ultra and Receive data on the S26 Ultra.
   * Connect the devices and select Contacts (you can also transfer messages, call logs, etc., if you wish).
   * Start the transfer - once it’s finished, open the Contacts app on the S26 Ultra and each entry should still show the correct “SIM 1” or “SIM 2” designation.

2. Check the default SIM settings - After the move, you may want to confirm which SIM is used for calls and messages:
   * Settings → Connections → SIM card manager
   * Here you can set the global default for Calls, Messages, and Mobile data

Hope that works for you 😊

Have a good day! ☀️