I have a Virtual Private Server (VPS) through Digital Ocean, and I'm using PuTTY to SSH to it. I have a Minecraft server, and whenever I launch the server, it creates a screen session.

Whenever I press Ctrl + A D or any other combination of A and D , nothing happens. I've tried Ctrl + Alt + D , Ctrl + A Ctrl + D , screen -D , and nothing seems to work.

Ctrl + A D only seems to work once every few dozen times I completely restart the server.

Ctrl + C works fine, but it also shuts off the Minecraft server. If I close PuTTY, it also closes the server. Is there any other way I can detach the screen, or have Minecraft auto-launch when the VPS starts up?

It's running on Ubuntu 16.04 64-bit.