void func()
{
int a = 0; // breakpoint here
}

int main()
{
std::thread t = std::thread(&func);
t.join();
return 0;
}

On break, it shows the main thread callstack and current position in main thread. You will have to switch to worker thread to see where actual breakpoint is triggered. Moreover, after pressing 'Step Over' or 'Step into', you will be switched to main thread back again. Definitely unwanted behaviour.