Why is my java code here behaving this way where it returns true while it should return false? why if I remove the bool expression it still not work?

Question

enter image description hereI included th image with the problem I have to solve; I thought it should be easy. And expected my code to work. Yet it didn't... I don't car a a lot about a solution as much as knowing what I did wrong

I know I need to start from right to left in reading the simple binary number(no encoding and not including negative values) as the power of 2 increases...but in this program it reads the binary number from left to right (like as a string)

import java.util.Scanner;

public class Main {
    
    

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner myScanner = new Scanner(System.in);
        
        System.out.println("Enter a 5-digit integer made of 0s and 1s:");
        String binaryNumber = myScanner.nextLine();
        
        int length = binaryNumber.length();
        int index = 0;
        int powerOfTwo =1 ;// 2^0
        int decimalNumber = 0 ;
        int currentChar = 0;
        
        
        boolean isValid = true;
        
        
        while(index < length && isValid) {
            
            currentChar = binaryNumber.charAt(index);
            
            if(currentChar > 1 /*Therefore not a 0 or 1*/) {
                isValid = false;
                System.out.println("Error at index "+index+" which is "+binaryNumber.charAt(index));
            }
            
            decimalNumber += (binaryNumber.charAt(index) * powerOfTwo) ;
            powerOfTwo*=2;
            index++;
        }
        
        if(isValid) {
        System.out.println(binaryNumber+" in decimal is "+decimalNumber);
        }else {
            System.out.println(binaryNumber+" is not valid ");
        }
        

    }
    
    
    

}

I tried removing where th script checks if a character is a (0 or 1) or not. if (currentChar > 1 /*Therefore not a 0 or 1*/){....

Then it started calculating binary numbers like 0000 to be more than 0.