深度复制向量时，向量迭代器不兼容

I am running into this "vector iterators incompatible" assert and I have no idea why. I looked at few answers here but none of them helped. I wonder if anyone can spot the issue. It is basically a vector that I am deep copying, but when I iterate through the copy, it asserts. Code is a bit confusing, but I could not re-pro with a simpler case:I am running into this "vector iterators incomp