This could be in connection to your sim card or mobile network infrastructure.
It maybe beneficial to have a conversation with your networks customer service's.
I've seen instances like this which usually clear up themselves.
I'm not aware of any setting or preference that would push a text message twice when using the Samsung Messaging App.
As a process of eliminationcan can you try the sim card in another phone.
I wish all the best.
Daily Driver > Samsung Galaxy s²³ Ultra 512Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "