Cannot assign to read only property '0' of object '[object Array]

switch (e.target.value) {
      
      case '1': setSortedStore((prev:any) => {
       
        const newArray = [...prev];
        const newSort = [...newArray[0].slice().sort((a:any,b:any) => { return a[0] - b[0]})]
        newArray.splice(0,1,newSort);
        return newArray;
      });
        break;
}