I don’t think this is something new. When you alt-tab away from a game it will release the graphics device and reacquire it when you tab back. Vorpx, in turn, has to release it’s hook and reacquire it, which doesn’t always work as intended.
You can try running in windowed mode instead of fullscreen or vice versa – it might make a difference. If you need to run a script, as a workaround, you can set a shortcut key in windows 10 or use a 3rd party hotkey utility.