Check if a graph is bipartite given adjacency matrix of the graph

Question

The code below is returning true for connected bipartite graphs but false for unconnected bipartite graphs. It's failing the test case for graph [[1,3],[0,2],[1,3],[0,2]].

class Solution {
public:
    bool isBipartite(vector<vector<int>>& graph) {
        int n = graph.size();
        vector<int> visited(n, 0);  // Using a vector for visited instead of an array
        
        for (int j = 0; j < n; j++) {
            if (visited[j] == 0) {  // If the current node is unvisited
                if (bfsTraversal(graph, j, visited) == false) {
                    return false;
                }
            }
        }
        
        return true;
    }
    
    bool bfsTraversal(vector<vector<int>>& graph, int startNode, vector<int>& visited) {
        queue<pair<int, int>> bfs;
        bfs.push(make_pair(startNode, 1));
        visited[startNode] = 1;
        
        while (!bfs.empty()) {
            int row_num = bfs.front().first;
            int color = bfs.front().second;
            bfs.pop();
            
            for (int i = 0; i < graph[row_num].size(); i++) {
                if (graph[row_num][i] == 1) {
                    if (visited[i] == color) {
                        return false;
                    }
                    if (visited[i] == 0) {
                        visited[i] = -color;
                        bfs.push(make_pair(i, -color));
                    }
                }
            }
        }
        
        return true;
    }
};

So I have used a queue in which I am storing the node and its corresponding color which and a visited vector to store the color of each node on bfs traversal. I am coloring nodes differently which are adjacent to each other and nodes which are not colored are denoted as 0 in visited vector. I'm using two colors denoted as -1 and 1. The code is giving correct result for connected graph but not so in the case of unconnected graph.