What wrong with my solution to combination sum problem

Question

why is my code not working for inputs [2,3,5],Target =8. Have debugged this so many times but cant understand y at some point sum becomes 3 while the only element in the list is equal to 2. https://leetcode.com/problems/combination-sum/

class Solution {
    public List<List<Integer>> combinationSum(int[] candidates, int target) {            
        List<List<Integer>> ans = new ArrayList<>();            
        combine(candidates,target,new ArrayList<Integer>(),ans,0);
            return ans;
        
    }
    
    public void combine(int[] candidates, int target,List<Integer> curr, List<List<Integer>> ans,int sum)
    {
        if(sum>target)
            return;
        
        if(sum==target)
        {
            if(!isexists(curr,ans))
            {
                List<Integer> temp = new ArrayList<>(curr);
                Collections.sort(temp);
                    ans.add(temp);
            }           
          
            return;
        }
        
        for(int c :candidates)
        {
            curr.add(c);
            sum=sum+c;            
            combine(candidates,target,curr,ans,sum);
            curr.remove(curr.size()-1);
            sum=sum-c;                
        }     
                
    }
    
    public boolean isexists(List<Integer> curr, List<List<Integer>> ans)
    {
        Collections.sort(curr);            
        for(List<Integer> l:ans)
        {
            if(l.equals(curr))
                return true;                
        }            
        return false;            
    }        
}