Thanks Henrik, it's working for me too after adding "video=HDMI-A-1:e" in my case.
- Bug#894731: linux-image-4.15.0-2-amd64: Setting d... Henrik Friedrichsen
- Bug#894731: linux-image-4.15.0-2-amd64: Sett... Ricardo MartÃn Camarero
- Bug#894731: linux-image-4.15.0-2-amd64: Sett... Andreas Schreiner
- Bug#894731: linux-image-4.15.0-2-amd64: Sett... Henrik Friedrichsen
- Bug#894731: linux-image-4.15.0-2-amd64: Sett... Henrik Friedrichsen
- Bug#894731: linux-image-4.15.0-2-amd64: Sett... Ricardo Martin Camarero

