I have attached 2 screenshots that shows CyberDuck app crashing at launch on my mac asking to reinstall on apple store,
but I can't do so because Apple Store doesn't recognise that I already bought it.
You will have to contact Mac App Store support if you can re-download after switching regions. You could try to choose to Buy again and from my own experience it will usually recognise the previous purchase. Otherwise I can offer you a registration key to be used with the version available for download from https://cyberduck.io. In that case please write to email@example.com