Why Visual Studio and Dev-C++ does not destroy local variable and other IDEs does: C++

I have a very basic question, I don't know it was asked before or not? I have tried to find the answer but could not get it.

I am using C++ with different IDEs, like Visual Studio 2019, code blocks, Dev C++ and online compiler named as OnlineGDB.

I have simple code here.

#include <iostream>

int* getInt(){
    int x = 10;
    return &x;
}

int main()
{
    int *ptr = getInt();
    std::cout<<*ptr;
    return 0;
}

As we know x is a local variable in getInt and when getInt function finish x will be destroyed by the concept of local scope. I am returning reference of x and storing in a pointer which is in main. Now by the book it should not print anything or a garbage value because x is destroyed.

But when I run this code in different IDE they gives different results. Lets see the results.

In OnlineGDB:

warning: address of local variable ‘x’ returned [-Wreturn-local-addr].

It shows this warning and does not print any thing.

In Dev-C++ 5.7.1:

warning: address of local variable ‘x’ returned [-Wreturn-local-addr].

It shows this warning but also print the value 10.

In code blocks:

warning: address of local variable ‘x’ returned [-Wreturn-local-addr].

It shows this warning but does not print any thing.

In Visual Studio 2019: It does not show any warning and print the value 10.

So what is actually happening under the hood, what am I missing? Why same code have different results in different environment.