RealVNC Server does not start on Raspberry Pi unless a mouse/keyboard are connected

If you do not have a keyboard or mouse connected to your Raspberry Pi, RealVNC Server may not start automatically despite being enabled.

This is usually caused by the Raspberry Pi not having enough entropy, preventing RealVNC Server and other services from starting.

To resolve this you will need to install another entropy generator such as haveged which you can install by running the below command:

sudo apt install haveged